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UN
oIt
DERMAL AND OCULAR EXPOSURE
DURING THB SPRAY APPLICATION OF
SELECTED INDUSTRIAL CIIEMICALS
A thesis submitted for
the degree of
DOCTOR OF PHILOSOPHY
The Department of Public Health. Faculty of Health Sciences,
The University of Adelaide, South Australia
Su-Gil Lee
B.Sc. (Ilons), M.S.E.
tn
by
November 2004
DECLARATION
I declare that this thesis contains no material which has been accepted for the award of
any degree or diploma in any university or other tertiary educational institution; and that
to the best of my knowledge and belief it contains no material previously published or
written by another person except where due reference in made in the text of the thesis.
The experimental work described herein was carried out from 2001 to 2004 in the
Department of Public Health, University of Adelaide. Some of the results of this thesis
have been presented at the 21't Annual Conference of the Australian Institute of
Occupational Hygienists (December 2003).
Experiments and studies on volunteer workers described in this thesis were canied out
with the approval of the appropriate ethics committees of the University of Adelaide and
Flinders University.
I consent to this thesis being made available for photocopying and loan if accepted for the
award of the degree of Doctor of Philosophy.
Su-Gil Lee
ACKNOWLEDGEMENTS
There are many people who generously assisted me in my work.
First of all, I would like to express my appreciation to my supervisors Dr. Dino Pisaniello
and Dr. John Edwards for their provision of critical and thoughtful academic guidance,
and to Dr. Michael Tkaczuk for technical advice during my study.
I acknowledge the participation of Primary Industries and Resources South Australia
(PIRSA) and the Motor Trade Association (MTA) in South Australia in facilitating the
field work.
I would also like to thank all my colleagues and friends in the Department of Public
Health at the University of Adelaide.
11
ABSTRACT
Use of chemicals may entail exposure by the dermal or ocular route, and there rs a
shortage of data pertaining to those routes. Spray application of chemicals poses a special
problem since workers may experience signif,rcant skin, ocular and inhalational exposure.
This study addresses exposure during spraying of malathion and fenthion insecticides for
fruit fly control and hexamethylene di-isocyanate (HDI) - based paint in the automotive
and furniture industries. The research aims to characterize exposures and symptoms, and
assess the adequacy of personal protective equipment under field conditions.
Pest control workers participated in an exposure simulation and were subsequently
monitored during a fruit fly outbreak. Exposure assessment entailed air sampling, dermal
exposure and biological monitoring. Sampling of lacrimal fluid was also conducted.
Painters using isocyanates were assessed by dermal, air and ocular monitoring.
Health and work practice questionnaires were used for both groups, along with
observation of job tasks and the work environment. Glove permeation tests, under
conditions of variable use, temperature and active ingredient concentration were also
conducted.
Questionnaire data did not suggest an excess of symptoms among fruit fly control
workers, compared with controls. However, isocyanate-exposed painters experienced
more skin and respiratory syrnptoms.
Insecticides were coÍìmonly detected in glove samples, on the forehead, and on the
forearm, shoulder and chest regions. In the case of isocyanate spray painting, apprentices
appeared to have higher skin exposures, associated with poorer work practice.
In general, glove performance was found to be influenced by glove type, thickness,
repeated use and temperature.
Ocular exposure was detectable in many cases, but appeared to be strongly dependent on
whether full face respiratory protection was worn.
111
Although there was evidence for dermal and inhalational exposure for workers exposed
to malathion and fenthion, biological monitoring data are consistent with generally low
uptake under the circumstances investigated.
Inhalational exposures to HDl-based paint aerosols were potentially significant, and there
was evidence of exposure by the dermal and ocular routes.
Permeation and thickness data show that glove performance may deteriorate with
increased usage and temperature, and it is suggested that attention be paid to differential
wear patterns associated with the task and worker handedness.
1V
TABLE OF'CONTENTS
DECLARATION
ACKNOWLEDGEMENTS
ABSTRACT
TABLE OF CONTENTS
LIST OF FIGURES
LIST OF PLATES
LIST OF TABLES
LIST OF STUDY GROUPS
ABBREVIATIONS
CHAPTER 1. GENERAL INTRODUCTION
1.1 Introduction..._.__.___
L.2 Exposure Pathways for Chemicals
1.2. 1 Introduction _...__._--
l.2.2Dermal Contact
1.2.3 Ocular Contact
1.3 Classes of Chemicals that may be Significantly Absorbed Through
1
_.._.il
111
V
XV1
XV11
XV111
XXIl
XX111
1
3
aJ
J
5
7the Skin and Eye__
1.4 Assessment of Chemical Exposure...-.-.-.
1.4. I Inhalational Exposure Assessment
1.4.2 D ermal Exposure Assessment....
1.6.1 Introduction
I .6.2.4 Respiratory effects.-.-...-
1.6.2.5 Genotoxicity and cancer--...---
1.6.2.6 Other effects
1.6.3 Exposure Criteria.
1.6.4 Previous Research
7
7
8
131.4.3 Ocular Exposure Assessment-.---------
1 .4.4 Biological Exposure Assessment ----------.-- t4
1.4.5 Evaluation of Chemical Protective Clothing- l4
1.5 Selection of Chemicals and Processes 15
1.5.1 Industrial Processes where Skin and Eye Exposure is Likely.- 15
1.5.2 Modeling of Skin and Eye Exposure during Spray Application..........-.-..-.-..15
1.5.3 Selection of Chemicals for this Research 18
1.6 Organophosphate Pesticides (Malathion, Fenthion) Used for the Control of the
Mediterranean Fruit Fly_.........._- 2T
21
L6.2 Ovewiew of Health Effects 26
1.6.2.1Absorption, distribution, metabolism and excretion 27
1.6.2.2 Mechanism of toxicity. 28
1.6.2.3 Skin, eye and mucous membrane effects 29
30
30
31
32
34
Vl
1.7 HDI-based Isocyanates in Automobile and Furniture Industries- _ -_._.
1.7.1 Introduction
1.7.2 Ovewiew of Health Effects
1.7.2.I Absorption, distribution, metabolism and excretion 42
39
39
4I
1.7.2.2 Mechanism of toxicity__ 43
I.7.2.3 Skin, eye and mucous membrane effects 43
1.7.2.4 Respiratory effects excluding asthma 44
I.7.2.5 Occupational asthma 44
45
45
1.7 .2.6 Genotoxicity and cancer
1.7.2.7 Other effects
1.7.3 Exposure Criteria.__..
1.7.4 Previous Research
1.8 Purpose of the Study and Research Questions__-___
1.8.1 Purpose of The Study.....__..
1. 8.2 Research Questions.._..-..._...-...
CHAPTER 2. DERMAL AND OCULAR EXPOSURE TO
ORGANOPHOSPHATE PESTICIDES USED IN
F'RUIT FLY ERADICATION
2.L lntroduction
2.2 Study Populations._._-___.
2.2.1 Study Group 1 (Field Simulation Trial, 2001)
46
46
51
51
53
55
55
vrl
2.2.2 Study Group 2 (Fieldwork during Fruit Fly Outbreak, 2003) ____-_.-_-
2.3 Methods
2.3. t Fieldwork Methods
58
58
58
2.3.l.lQuestionnairesuley(StudyGroup 2)--..-. _____.__._-_____-.58
2. 3. I . I . I D evelopment and pilot inves tigation - _ -_. __ _ _. _ _ _ _ -_____--__._...._ 5 8
2.3.1.1.2 Administration and human ethics 59
2. 3. 1. 1. 3 Data analysis
2.3.1.2 Worksite observations
2.3.I.4 Dermal and ocular monitoring ___--__
2.3.I.5 Biological monitoring
2.3.2.2 Glove testing...__.._
2. 3. 2.2. I Glove materials
60
60
2.3.I.3 Environmental measurements 60
2.3.1.3.1 Air monitoring (Study group I only)-___.-__ ......60
2. 3. I. 3. 2 Surface monitoring. 6I
61
63
2.3 .2 Laboratory Methods -..._.-___ _. 64
2.3.2.1 Method development._-._-..__...-.-.._____ 64
2.3.2. 1. 1 OVS tube sampler.___._ 65
2. 3. 2. L 2 Degradation experiments 65
2.3.2.1.3 Test cellfor gloveperþrmance assessment_._._-_-__....--.....65
2.3.2.1.4 Preparation of the glove materials 66
2. 3.2. 1. 5 Collecting medium ---___--____ 67
68
68
2.3.2.2. 2 Breakthrough times and permeation rates ...._...
2. 3. 2. 2. 3 Thiclcness measurement
68
v11l
69
2.3 .3 Ãnalytical Methods ___________-.._-_
2.3 .3 .l Gas-chromato graphy-.
2.3 .3 .2 Hi gh-p erfoÍnanc e liquid chromato graphy
(Glove permeation tests)______. ___
2.3 .4 Limits of Detection
69
69
69
2.4 Results
70
70
702.4.1 Work Practices
2.4.2 Suwey Results_..
2.4.2.5 Knowledge and training
2. 4.3 E,nv ironmental Measurements
2.4.3.1 Study group 1 (2001)..-..
2.4. 3. l. I Observations
2.4. 3. 1. 2 Air monitoring
2.4.3.1.3 Overalls
2.4.3,1.4 PPE monitoring ._._
2.4.3. I. 5 Ocular monitoring
2.4. 3. 1.6 Biological monitoring
2.4.3.2 Study group 2 (2003).-..
2.4. 3. 2. I Observations
2.4.3.2.2 Head wipe and PPE monitoring
7l
2.4.2.1Subjects 7t
2.4.2.2 Symptom prevalence________ 72
2.4.2.3 Accidental exposures_. 72
2.4.2.4 Use of p ersonal protective equipment __ _- _ _ __-_ __ _ 73
74
75
75
75
75
76
77
77
17
78
IX
78
2.4.4 Lab oratory Analysis 79
2.4.4.I Optimized analytical conditions 79
2.4.4.1.1 Desorption fficiency of ){AD-2.__ 79
2.4.4.2 Glove testing __.. 83
2. 4. 4. 2. 1 Effe c t of temp er atur e ( 3 0 % Is op r opy I Al c o h o l) . _ _ _ _ _ _. _-_.. _.8 3
2.4.4.2.2 Performance of used PVC gloves.__ 85
2.4.4.2.3. Thiclntess changes observed during use..----.--__._-....-..._.__87
2.5 Discussion
2.6 Conclusions
87
92
CHAPTER 3. DERMAL AND OCULAR EXPOSURE TO
HEXAMETTIYLENE DIISOCYANATE (HDI).
BASED PRODUCTS
3.1 Introduction 93
3.2 Study Populations.____.__._-.____. 93
3.2.1 Study Group 3 (Crash Repair Shops & Associated Industries, 2003)..-_..._-_-94
3.2.29tudy Group 4 (Furniture Industry,2004) 95
X
3.3 Methods 96
963.3. 1 Fieldwork Methods
3.3. 1.1 Questionnaire survey.
3. 3. 1. 1. 1 Development and pilot investígøtion_______.
3 . 3.'1 . I .2 Administration and humqn ethics
96
96
97
97
97
3. 3. 1. 1. 3 Data analys,s........___.____
3.3.1.2 Worksite observations
3.3. 1.3 Environmental measurements
3. 3. 1. 3. 1 Air monitoring_.__________._
3. 3. 1. 3. 2 Surface monitoring.
98
98
3.3.1.4 Dermal and ocular monitoring 100
3.3. 1.5 Biological monitoring 101
3.3.2 Laboratory Methods _.._..-____ 101
3.3.2.1 Method development.._.______.____ 101
3.3.2.1.1 HSE method (MDHS-2ï, UK)_.___. 101
3.3.2.1.2 SamplingJìlter._-.-......_. _____._____.-..103
3.3.2.1.3 Absorbing solution (Derivatizing Sohtion).....-..-_........_104
3. 3. 2. 1.4 Dissolving solutions,... r04
3. 3. 2. I . 5 Ocular s ampling s o lution ( " Refres h " ey e drops)________-_1 04
3. 3. 2. 1. 6 GhostrM Wipes.--.---.. 105
3.3.2.1.7 Test cellfor glove performance assessment 105
3.3.2.L8 Preparation of the glove materials 106
3.3 .2.2 Glove testing._-_.___.-. 108
3. 3. 2. 2. 1 Glove materials
X1
108
3.3.2.2.2 Permeation test of the glove møterials ._____-____.--___.______.__108
3.3.2.2.3 Breakthrough times and permeation rates 109
3. 3. 2. 2. 4 Fatigue testing_ _. _. _...... _-. 109
3.3.3 Analytical Methods ....-.-...-..--- 110
3.3.4 Limits of Detection
3.4 Results
111
111
1113.4.1 Work Practices
3.4.2 Survey Results____
3.4.2.1 Subjects.__._
3.4.2.2 Symptom prevalence
3.4.2.3 Accidental exposures__
3.4.2.4 Use of personal protective equipment-____-__-_-__
3 .4.2.5 Knowleclge and training... -...-__.... -. _ _.
3.4.3 Environmental Measurements
3.4.3.1, Study group 3 ______-.__.__.._.__.____
3.4. 3. 1. I Observations
lt2
t12
lt4
115
11s
TI7
118
118
118
3.4.3.1.2 Air mon 118
3.4.3.1.2.1 Spraying in a booth._ 118
3. 4. 3. 1. 2. 2 Spraying outs ide of the booth _- -. -. _ _. _. _-. --_ _ - - _- _- _ _ll9
3.4.3.1.3 Dermalandsurfacemonitoring ____________--___._120
3.4.3.1.3.1 Indoor spraying____ ____-_120
3. 4. 3. 1. 3. 2 Outdo or and mobile spraying.. -- --_. -- __ - - _ _ _ _ - _- - _ _ - -I22
3.4.3.L3.3 Surface monitoring -.__123
3.4. 3. 1.4 PPE monitoring ..
x11
124
3.4.3.1.4.1[ndoor spraying_-_. I25
3. 4. 3. 1 . 4. 2 Outdoor and mobile spraying.. -- - - -. -- - - -. -. - -- - -. - - --126
1273.4. 3. 1. 5 Oculør monitoring.
3. 4. 3. 1. 5. I Indoor spraying----------
3.4.3.2 Study group 4 ._._..____....__..
3. 4. 3. 2. I Obs ervations
3. 4. 3. 2. 2 Air monitoring.-.
t27
t28
t28
t28
3. 4. 3. 1 . 5. 2 Outdo or and mobile spraying. -. -.............---....-- 1 28
3.4.3.2.3 Dermal and surface monitoring ----------.---.-..-129
3.4.3.2.4 PPE monitoring.__....._.... 131
3.4. 3. 2. 5 Ocular monitoring t32
3.4.4 Laboratory Analysis t32
3.4.4.I Optimized analytical conditions-- t32
3.4.4.1.1 Absorbing solution (Derivøtizing Solution) ---.------.-.-.--.-I32
3,4.4.1.2 Dissolving solutions.--- --....-.-......133
3. 4. 4. 1 . 3 O cular s ømpling s olution ( " Refres h " ey e drops).--.-.--.. 1 3 3
3.4.4.1.4 GhostrM Wipes 134
3 .4.4.2 Glove testing..._._.. 135
3.4.4.2.1 Effect of solvents on selected gloves 135
3.4.4.2.2 Effect of hardener strength on isocyanate permeation..l36
3.4.4.2. 3 Fatigue test __.__-..___. r37
3.5 Discussion 137
t433.6 Conclusions
x11l
CHAPTER 4. GENERAL DISCUSSION
4.L Dermal and Ocular Exposure during Spraying Processes.-__
4.2 Further Study._____
REF'EREI{CES
APPENDICES
t45
t47
Appendix 1.
Appendix 1.1
Appendix 1.2
Appendix 1.3
Appendix 2.
Appendix 2.1
Appendix2.2
Appendix 2.3
Appendix 2.4
149
Information Sheets, Consent and Complaint Forms_.._.__....__.- 180
Information sheet for fruit fly eradication workers.____ .-___ _.__..___180
Information sheet for HDl-exposed workers ._ -___..____181
Consent form for fruit fly eradication workers and
HDl-exposed workers ____.__-_____182
Appendix 1.4 Complaintform.__-___-________ 183
Questionnaires-.__..____ ____.___.... 184
Questionnaire for fruit fly eradication workers_____ _....184
Questionnaire for isocyanate spray painters_.__. _-_--.-__-192
Questionnaire for unexposed workers (Controls)._ -_-__2Ol
Glove usage questionnaire for fruit fly eradication workers________211
Appendix 3.
Appendix 3.1
Ethics Approval__ 212
Flinders clinical research ethics committee (69102)_._--_.--.--_.---..---212
xlv
Appendix 3.2 The human research ethics committee at the University of
Adelaide
Appendix 4.
Appendix 5.
Appendix 6.
.213
Cover Sheet of Laboratory Report from WorkCover New
South'Wales.... 215
Supporting Letter from Motor Trade Association..... ....216
Worksite Observation X'orm 217
XV
LIST OF'F'IGURBS
Figure 1 A Conceptual Model of Dermal Exposure
T6
Figure 2 Chemical Structure of Malathion
25
Figure 3 Chemical Structure of Fenthion
Figure 4 Toxic Mechanism of Organophosphates_____-_____
Figure 5 Chemical structures of HDI and HDI trimers
Figure 6 Dermal Exposure Sampling Positions___
Figure 7 Standard Test Cell and Set Up Equipment for Glove Permeating
Testing
Figure 8 Positions of Dermal Sampling for HDI-._-___.
Figure 9 Anal¡ical Test cell---.--.
25
29
40
62
66
100
106
Figure 10 Instrumental Setup for the Detection of Solvent Breakthrough by PID_._-......107
xvt
LIST OF'PLATES
Plate 1 Structure of The Human Skin
Plate 3
Structure of The Human Eye.------------
Spray Worker Applyng Pesticide__.
Plate 4
Plate 5
Plate 6
PIate 7
Plate 8
Plate 11
PIate 12
Plate 13
Plate 14
Plate 15
4
Plate 2 6
t9
64
10s
106
Spray Painter Applying Isocyanates.._... 21
Pesticides (malathion, fenthion) Application During Simulation in 2001-------56
Pesticide (malathion) Application During Outbreak in 2003 _____.._56
OVS Sampling Tube for Air Monitoring of Pesticide Workers.-....-.-.......-....--60
Cotton Pads for Dermal Monitoring and Surface Monitoring _..__-_61
Plate 9 Equipment for Ocular Monitoring 63
Plate 10 Equipment for Urine and Blood Sampling _
PVC Protector Safety Gloves Used for Fruit Fly Eradication Program._._ .----.-67
Two-Pack Spray Painting in Crash Repair Shops.___...-. -__--.--_-----_---94
'fwo-Pack Spray Painting in Furniture Industry.-... -._-_94
Air Monitoring Apparatus for Isocyanate (HDI)..-____.- ___.________-____--98
GMD Systems Paper Tape and Permea-TecrM gg
Plate 16 GhostrM Wipe Pads.-.
Plate I7 Glove Materials Used for Glove Performance Test
xv11
LIST OF'TABLES
Table 1 Compartment Descriptors of the Conceptual Model...--...-...----- l7
Table 2 Common Organic Isocyanates Diisocyanates and Physical Characteristics----39
Baseline Variables for Pesticides Workers and Controls 7ITable 3
Table 4 Work-related Symptom Prevalence Data --.. 72
Table 5
Table 6
TableT
Table 8
Accidental Exposures from Chemical Use Among Pesticide Workers.---- ---- 73
PPE Use and Work Practices Among Pesticide Workers 73
Glove Usage Among Pesticide Workers.--- --.-..-. .-.-..-.-74
Training and Education Among Pesticide Workers (Study group 2) --.-.-..-.-...74
Table 9 Air Sampling Data (2001) . .....
Table 12 Workers PPE Samples (undergloves, socks and hats, 2001)--
Table 13 Serum Cholinesterase Levels Pre- and Post Exposure (2001)
and Storage Method
Table 17
Table 18
Table 19
75
Table 10 Malathion Spray Workers' Overalls Samples (2001)..-- 76
Table 11 Fenthion Spray Workers' Overalls Samples (2001)--....-. .-.--...--..-.-76
77
78
TabIe 14 Malathion in Skin Wipe and Inner Cotton Gloves Samples (2003)----.--......-...78
Table 15 Desorption Efficiency of Malathion and Fenthion from OVS Tube
Components Using Toluene 79
Table 16 Recovery of Malathion and Fenthion from OVS Tubes by Time
80
Comparison of Different Mobile Phases to Detect Malathion by HPLC ---..-.-81
Sensitivity of HPLC UV Detector for Fenthion---- -.--.-81
Solubility of Malathion and Fenthion in Different Collecting Media-------- ------82
XV11I
Table 20 Breakth¡ough Times and Permeation Rates of PVC Glove Material
under Various Conditions
Table2l Breakthrough Times and Permeation Rates of New PVC Gloves with
Technical Grade and Working Strength Malathion__-..____
Table22 Breakthrough Time and Permeation Rate of Used PVC Gloves with
Technical Grade Malathion at22oC
83
84
86
Table23
Table24
Table 25
Table26
List of Items Used for Surface Wipes and Approximate Areas Wiped._____ _.--_.99
Reagent Systems for The Quantification of Airborne Isocyanates.._.....__-__ ___-I02
Baseline Variables for HDI Spray Painters and Controls 113
Chemical Usage and Application Among HDI Spray Painters..-_...__....._._.__-.. 1 1 3
Table 27 Work-related Symptom Prevalence Data (HDI Spray Painters).__ lt4
Table 28 Accidents from Chemical Use Among HDI Spray Painters 11s
TabIe 29 Use of Personal Protective Equipment Among HDI Spray Painters....__...__...116
Table 30 Training and Education Among HDI Spray Workers rt7
Tabl.e 31 Personal Isocyanate Exposure Concentrations of Spray Painters Inside
Spray Booths within Breathing Zone in Study Group 3 I19
Table 32 Personal and Fixed Position Isocyanate Concentrations Outside Spray
Booths in Study Group 3
Table 33 Isocyanate Dermal Monitoring of Indoor Spray Painters in
Table 34 Isocyanate Dermal Monitoring of Outdoor/Mobile Spray Painters in
Table 35 Quantity of Isocyanate on Surface Samples in Spray and Mixing Areas
120
l2l
t22
123
XlX
Table 36
Table 37
Table 38
Table 39
Isocyanate Indicator Paper Testing of Surfaces at Automobile Shops
by Using Paper Tape or Permea-Te"tt Pudr in Study Group 3................. ....124
Isocyanate Contamination Levels of Personal Protective Equipment (PPE)
for Indoor Spray Painters in Study Group 3._..._................. 125
Isocyanate Exposure from Personal Protective Equipment (PPE) for
Outdoor/Mobile Spray Painters in Study Group 3 --_._..__.__.__-
Isocyanate Ocular Exposure for Indoor Spray Painters in
t26
127
r28
Study Group 3__..._.___.___.__.._.____.
Table 40 Isocyanate Ocular Exposure for Outdoor/Mobile Spray Painters
Table 41 Personal Isocyanate Exposure Concentrations of Spray Painters Inside
Spray Booth in Study Group 4_ ___..______.
Table 42 Isocyanate Exposure Concentrations in General Area in
129
r29
Table 43 Isocyanate Dermal Monitoring of Spray Painters in Study Group 4______._-.____ 130
Table 44 Quantity of Isocyanate on Surface Sampies at Spray and Mixing Areas
Table 45 Use of Permea-TecrM Pads for Hand Monitoring of Spray Painters
Wearing Protective Gloves (Disposable Nitrile Glove-TNT) - Group 4 -_-__-l3I
Table 46 Isocyanate Ocular Monitoring of Spray Painters in Furniture Industry in
Study Group 4._____..____._.__-...___.
130
132
Table 47 Comparison Between Toluene and Methylene Chloride for Derivatizing
Solution
XX
133
Table 48 Isocyanate Extraction Efficiency of Different Acetonitrile:Methanol
Mixtures
Table 49 Rate of Decomposition of HDl-based Hardener in Ocular Sampling
Solution
133
134
Table 50 Efficiency of Isopropyl Alcohol as a Surface Wetting Agent-____.__............-...135
Table 51 Breakthrough Times of Glove Materials with Diverse Solvents 136
Table 52 Breakthrough Times and Permeation Rates of Selected Glove Materials
with Different Composition of Hardeners._.___________._ __________.____.._...137
Table 53 Proportion of Detectable Dermal Isocyanate Exposures by Body
Region 139
XXl
LIST OF'STUDY GROUPS
Group L:
Comprised fruit fly control workers participating in an exposure simulation at a
government field research station in 2001
Group 2:
Comprised fruit fly control workers carrying out baiting work during an outbreak in
Adelaide, South Australia in 2003
Group 3:
Comprised spray painters using isocyanate-based paints in private crash repair
workshops, apprentice training facilities, and in outdoor (i.e. out of bootþ and mobile
touch up spray painting situations
Group 4:
Comprised spray painters using isocyanate-based spray paints in a furniture
manufacturing company
xxll
AS
ACh
AChE
ACGIH
ADI
AM
AS/ITZS
ASTM
ATSDR
BALF
BCPC
BEIs
BM
BS
BSS
CAT
CFR
CNS
CVS
ABBREVIATIONS
Acetylcholine
Acetylcholinesterase
American Conference of Governmental Industrial Hygienists
Acceptable Daily Intake
Arithmetic Mean
Australian Standard
Australian/N ew Zealand St andard
American Society for Testing and Materials
Agency for Toxic Substances and Disease Registry
Bronchoalveolar Lavage Fluid
British Crop Protection Council
Biological Exposure Indices (ACGIH)
Biological Monitoring
British Standard
Balanced Salt Solution
Breakthrough Time
Catalase
Code of Federal Regulations
Confidence Interval
Central Nervous System
Cardiovascular System
D iethyl dithiopho sphate
BT
CI
DEDTP
XXl1I
DEHP
DEP
DETP
DDT
DHHS
DMDTP
DMP
DMTP
DNA
DNP
DREAM
DTNB
ECD
EPA
FDA
FEVr
FIVES
FRC
FVC
DS
EC
EN
Diethylhexyl Phthalate
Diethylphosphate
Diethylthiophosphate
D ichloro diphenyltrichloro ethane
Department of Health & Human Services, U.S. Public Health
Service
Dimethyldithiopho sphate
Dimethylphosphate
Dimethythiophosphate
Deoxyribonucleic Acid
2, -Diritrophenol
A Method for Semi-quantitative DeRmal Exposure AssessMent
Desorbing Solution
Dithiobis(2-nitrobenzoic acid)
Electrochemical Detector
Electron Capture Detector
European Committee
U.S. Environmental Protection Agency
U.S. Food and Drug Administration
Forced Expiratory Volume in One Second
Fluorescent Interactive Video Exposure System
Forced Residual Capacity
Forced Vital Capacity
Gas-ChromatographyGC
XXlV
GC-ECD
GC-FPD
GC-TSD
GI
GM
HVLP
HDA
HDI
HDI-IC
HDI-BT
HPLC
HPLC/MS
HPLC-UV
HPLC-EC
Gas-Chromato graphy with Electron Capture Detector
Gas Chromatography with Flame Photometric Detector
Gas Chromatography with Thermionic Specific Detection
Gastrointestinal
Geometric Mean
High-Volume Low-Pressure (spray painting system)
Hexamethylene-diamine
Hexamethylene Diisocyanate
HDI Isocyanurate Trimer
HDI Biuret Trimer
High Perforrnance Liquid Chromato graphy
High-Perforrnance Liquid Chromatography/Mass Spectrometry
High PerfoÍnance Liquid Chromatography with Ultra Violet
Detector
High PerfoÍnance Liquid Chromatography with Electrochemical
Detector
U.K. Health and Safety Executive
Immediately Dangerous to Life and Health
Immunofluorescence Analysis
Immunoglobulin E
Immunoglobulin G
Immunoglobulin M
Isopropyl Alcohol
Isophorone Diisocyanate
HSE
IDLH
IFA
IgE
IgG
IgM
IPA
IPDI
XXV
IR Infrared
Intergrated Risk Information System
Lethal Dose (50% population of test animals)
Lowest-Observed-Adverse-Effect Level
Limit of Detection
Human Breast Adenocarcinoma
Malondialdehyde
Methods for the Determination of Hazardous Substances
(uK HSE)
Methylene Bisphenyl Diisocyanate
Mobile Phase
Minimal Risk Levels for Hazardous Substances
Material Safety Data Sheet
Motor Trade Association, South Australia
U.S. National Cancer Institute
U.S. National lnstitute for Occupational Safety and Health
No-Observed-Adverse-Effect Level
National Occupational Health and Safety Commission (Australia)
Neuropathy Target Esterase
Occupational Asthma
Organisation for Economic Cooperation and Development
Occupational Exposure Limit
Occupational Health and Safety
1 -(2-methoxyphenyl)p iperazine
IRIS
LDso
LOAEL
LOD
MCFT
MDA
MDHS
MDI
MRL
MSDS
MP
MTA
NCI
NIOSH
NOAEL
NOHSC
NTE
OECD
OEL
OHS
OA
1-2MP
XXVl
PR
OP
OR
OSHA
PBPK
PChE
PCNA
PID
PIRSA
PPE
PTFE
PVC
RBC
REL
RfD
SCE
SOD
STEL
STD
TAFE
TDI
Organophosphate
Odds Ratio
U.S. Occupational Safety & Health Adminishation
Physiologically Based Pharmacokinetic
Plasma Cholinesterase
Proliferating Cell Nuclear Antigen
Photo Ionization Detector
Primary Industries and Resources, South Australia
Personal Protective Equipment
Permeation Rate
Polytetrafluoro ethylene
Polyvinyl Chloride
Red Blood Cell
Recommended Exposure Limit (US NIOSH)
Oral Reference Dose
South Australia
Sister Chromatid Exchange
Standardized Incidence Ratio
Superoxide Dismutase
Short Term Exposure Limit
Standard Deviation
Technical and Further Education
Toluene Diisocyanate
Therapeutic Goods Administration
SA
SIR
TGA
XXV11
TLC
TLV
TSD
TWA
wHo
UV
VC
Total Lung Capacity
Threshold Limit Value (ACGIH)
Thermionic Specific Detection
Time-Weighted Average
Ultraviolet
Vital Capacity
Volatile Organic Compounds
World Health Organization
VOCs
XXVIII
CHAPTER 1. GENERAL INTRODUCTION
l.L Introduction
For hundreds of years, it has been reco gnized that workers' health may be
compromised by work practices and conditions, and, in particular, chemical exposure.
For example, Paracelsus (1493-1541) wrote about miners' diseases, and, in 1700,
Ramazzini wrote "De Morbis Artificum" describing 53 occupational groups and the
diseases they experienced. Since then, work conditions have clearly improved, but
there remain situations where there is potential for chemical-induced occupational
mortality and morbidity.
In Australia, the National Occupational Health and Safety Commission (NOHSC) has
estimated around 2,200 deaths per year due to occupational exposures to hazardous
substances (Kerr et al., 1996; Morrell et a1.,199S). There has been debate about the
precise f,rgures (Christophers and Zammlt 1997). However, two more contemporary
studies, from Finland (Nurminen and Karjalainen,200I) and USA (Steenland et al,
2003), using a similar approach to Kerr, estimated a higher incidence of deaths
resulting from occupational diseases. If the attributable fractions from these studies
are directly substituted into the NOHSC profile, the revised estimates are 3,200 and
6,100 using the US and the Finnish fractions respectively.
Gun et al (1996) reviewed the occurrence and causes of occupational injury and
disease in South Australia. Apart from the continuing burden of asbestos-related
disease, acute injury and skin disease are probably the most common problems
associated with chemical exposure. Large numbers of workers are potentially
exposed. To take one example, there are approximately 2,000 hairdressing salons in
South Australia using various dyes, detergents and spray-on products.
Overall, chemical exposure represents a signihcant public health issue, and there is an
ongoing need to reduce occupational and environmental health risks that arise during
the manufacture, processing, use and disposal of chemicals. Various legislative
arrangements exist in Australia, notably the regulations, codes of practice and
guidance documents relating to the control of hazardous substances.
1
The National Code of Practice for the Control of Hazardous Substances (NOHSC,
1994a) outlines how to identify, assess, control and review risks to health from
exposure to hazardous substances in the worþlace. Under the Hazardous Substances
Regulations are three main strands, i.e. information provision, risk assessment and
hazard control.
Information provision includes :
o Material Safety Data Sheets (MSDS)
o Labels
o Emergency information
Risk assessment involves:
¡ Process review, including the identification of hazardous substances
o Exposure assessment and comparison with exposure criteria
¡ Assessment of the effectiveness of controls
o Consideration of the work-relatedness of any reported health effects
Hazard control, based on a hierarchy of controls, includes:
r Design or engineering solutions (elimination, substitution, minimization,
isolation, ventilation)
¡ Administrative controls (training, policies and procedures, and work
practices)
¡ Use of appropriate personal protective equipment
The National Occupational Health and Safety Commission (NOHSC, I994b) and
other agencies provide guidance on the minimization of occupational health risk due
to exposuretohazardous substances. A key component of risk assessment is exposure
assessment, which entails establishing the pattern of use of the chemical(s) and
identifying sources/routes of occupational exposure. Exposure assessment is often
qualitative or semi-quantitative, i.e. there is insufficient information available to
provide reliable quantitative estimates.
2
1.2 Exposure Pathways for Chemicals
1.2.1 Introduction
Chemicals enter the body by three main routes, i.e. the lungs (inhalation), the skin
(dermal absorption) and the mouth (ingestion). Ocular exposure and injection may
also occur in some situations. The intemal organs most commonly affected are the
liver, kidneys, heart, nervous system (including the brain) and reproductive system.
The relative extent of exposure by various routes is not always well understood.
Inhalational exposure assessment has been the traditional focus of attention, and
relevant standards have been in existence for most of the 20th century. However,
dermal exposure may be more important in many cases (Fiserova-Bergerova, 1993;
Boeniger, 2003; Semple, 2004; Van Hemmen, 2004). In recognition of this, the
American Conference of Governmental Industrial Hygienists (ACGIH) and other
standard setting bodies, have introduced skin notations. At present, there are no
dermal exposure standards or ocular standards, although some attempts have been
made to develop quantitative dermal occupational exposure limits (Bos e/ al, 1998;
Brouwer et al,1998), complementary to inhalational exposure limits.
Dermal exposure can lead to adverse health effects, such as dermatitis, irritation,
sensitization and systemic effects. Some chemicals, e.g. organic solvents, cause
dehydration andlor defatting of the skin, making it a less effective barrier. In the case
of the eye, chemical exposure to the eye can lead to a wide range of effects on the eye
and adjacent structures. These effects include lacrimation, ciliary muscle effects, and
conjunctivitis, to mention just a few (Piccoli et a|,2003).
In general, the respiratory dermal and ocular structures may be considered as both a
target organ andaportal ofentry.
l.2.2Dermal Contact
Once dermal contact occurs, the chemical may penetrate the skin, remain on the skin
or evaporate, as in the case of many volatile substances.
The skin is the largest organ of the human body by area (Plate 1), and comprises the
epidermis and dermis. The stratum corneum, the upper most layers of the epidermis
J
and dermis provide the barrier function for the skin (Schaefer and Redelmeier,1996;
Pugh et a1.,1998).
Plate 1: Structure of The Human Skin
(Sourced from: Skin biology and structure, www.mydr.com.au/default.asp?Article:3718)
Basically, there are three main pathways through the stratum corneum, namely the
trans-appendageal route, the intercellular route througþ the lipid domain between the
corneocytes and the intracellular route through the comeocytes. The trans-
appendageal route entails the sebaceous ducts, hair follicles and sweat ducts.
According to some researchers, lipophilic chemicals use the intercellular route as the
main pathway (Montagna and Lobitz, 1964; Schaefer and Redelmeier, 1996). Even ifthere is no active transport mechanism, chemical absorption is controlled by
permeation. The rate of permeation depends on the concentration gradient, and thus
immersion in a liquid chemicals is much more hazardous than sparse droplet
deposition, which is in turn, less hazardous than gas or vapor dermal exposure.
Occlusion of liquid chemical in gloves may be tantamount to direct liquid immersion
and potentially represents a serious dermal exposure risk. The combination of
elevated temperature and increased blood flow to the skin in hot weather may
exacerbate dermal absorption andlor accelerate diffusion rates.
4
Grünular cell låyer
Spinous layer
Éasal cell layer
Sebaceous glend
Swest duct
Erector pili muscleSweat gland
Collagen andelastin fibres
Hair fcllicle
Epidermis -l
Dermis -
å Subcr¡taneous fat
Élood vesselNerves
Hair
Stratum corneum
The main components of the stratum corneum arc 40o/o protein, 40o/o water and 20o/o
lipids (Schaefer and Redelmeier, 1996). It is composed of cotneocytes (horny layer
cells), and flattened non-nucleated keratinocytes (Touitou et al., 2000). The
underlying viable epidermis consists of keratinocytes, melanocytes, merkel cells and
langerhans cells. (Montagna and Lobttz, 1964; Schaefer and Redelmeier, 1996).
Metabolic enzymes exist in the epidermal layer.
In a human study (V/illiams, 1993), methyl ethyl ketone (MEK) was rapidly absorbed
through the skin into the blood. Due to the solubility in water, MEK absorption
through sweaty skin was faster. Even though inhalational exposure was low, i.e. about
I0o/o of the amount applied to the skin, 90% was excreted in the urine as both MEK
and its metabolites, and suggesting a significant dermal metabolism.
There have been several in vitro and in vivo studies of skin permeability (Morimoto
et al., 1992; Kao et al., 1985; Beckley-Kartey et al., 1997; Tupker et al., 1997;
Bronaugh et al., 1982). There are also predictive models to support understanding of
skin penetration (Tsuruta, 1990; Potts and Guy, 7992; Auton et al., 1994; Leung &'
Paustenbach,1994; Bookout et al.,1996; Wilschut et a1.,1996; Kissel, 2000). T'hese
mathematical models are based on physicochemical properties of the compound.
1.2.3 Ocular Contact
The eye is composed of derivatives of surface ectoderm (corneal epithelium and
conjunctiva) and of mesoderm (choroids, iris and ciliary body stroma) (Plate 2). The
eye contains vascular areas and an aqueous system.
The ocular surface is moisturized at all times. The sebaceous meibomian glands in the
lids create the outermost lipid layer, which is typically less than 0.1 micron thick. This
layer prevents evaporation of the tear film and lubricates the eyelid. Meibomian lipids
are composed of waxy and cholesterol esters (Holly and Lemp, 1987). The aqueous
layer constitutes around 90Yo of the thickness of the tear film and is generated by the
main lacrimal gland and the accessory lacrimal glands of Krause and V/olfring (Bron,
1985). The innermost layer of the tear film is the mucous layer, secreted by goblet
cells. This hydrated glycoprotein layer makes the corneal surface hydrophilic and thus
wettable and decreases surface tension of the tear film. The breakup of tear film is by
5
contact between the lipid and mucous layers or local breakdown of the mucous layer
(Lin and Brenner, 1982; Sharma and Ruckenstein, 1982).
SusÞensory
Anterior chambercontaining aqueoug
Pup¡l
Corner
(culouredpart of eye)
F osteriorcharnher
Sclera (ultite of e'¡æ)
hnroid
Retina
o\€a
rs
ñ ner!E
Cilisry b,rdy(r':rrtsininlt c¡lirn uscl e)
EI sÌrot
T of rectus tnustleary
Plate2: Structure of The Human EYe
(Sourced from: Structure of the eye, www'mydr.com.au/default.asp?Article:3429)
Chemical absorption through the eye may entail absorption through any or all of the
ocular structures including eyelids, mucous membrane, conjunctiva and eyeball,
although common terminology refers to the exposed eyeball and conjunctiva.
Chemicals absorbed through the eye may enter the bloodstream (Grant, 1974;
Klaassen et a1.,2001). Systemic effects from ocular exposure may also be via nasal
and alimentary mucosa. However, it has been found that short term effects are most
common, and usually mediated by the interaction of the chemicals with the ocular
surface. The principal mechanisms have been summanzedby Piccoli et al (2003).
The lacrimal gland produces water in response to stimuli on the ocular surface and in
so doing changes the lacrimal film composition. Blinking can also alter the precorneal
tear film, protecting the outer eye from external factors.
There appears to be limited information regarding ocular exposure to industrial
chemicals, as well as the relationship between dose, response and exposure limits.
6
1.3 Classes of Chemicals that may be SignifÏcantly Absorbed through the Skin
and Eye
There are potentially many substances that may be absorbed through the skin. The
ACGIH Threshold Limit Values (TLV) Booklet (2001) identifies varied classes of
substances, such as alcohols, nitriles, organochlorine insecticides, aromatic amines,
organophosphate insecticides, phenols, sulphoxides, carbamates, hydrazines and
glycol ethers. Of the substances, dimethyl sulphoxide is notable in that it is used as a
carier for chemicals that are meant to be absorbed through the skin.
Approximately 27Yo of substances on the ACGIH TLV list have a skin notation
indicating the significance of the issue.
In respect of ocular exposure, approximately 3o/o of the ACGIH TLVs are explicitly
based on eye effects, e.g. silver, methyl silicate, naphthalene, disopropylamine, diquat,
methanol, triethylamine and hydroquinone (Klaassen et a1.,2001). However, many or
most of the substances on the TLV list may cause eye irritation, as a secondary effect.
The amount of absorption through the eye is particularly poorly understood, and there
is a need for further research.
1.4 Assessment of Chemical Exposure
Although inhalation has traditionally considered to be the main route of exposure,
skin absorption can be important (Semple, 2004), and variety of direct and indirect
approaches have been developed to assess the significance of the dermal route. This
section outlines some common techniques for chemical exposure assessment,
including the use of biological monitoring as an integrated measure. It does not
specifically consider ingestion or inj ection.
1 .4. 1 Inhalational Exposure Assessment
If inhalation is the only significant route of entry into the body, then the results of air
sampling in the "breathing zoîe" may provide a good indication of personal health
risk. Typically, a lapel-mounted sampling head (e.g. sorbent tube or particle filter) is
7
connected to a calibrated battery-powered air sampling pumP, and this arrangement is
wom throughout the relevant time period, often an 8-hour shift or 15-minute short
term exposure period.
Air sampling approaches, equipment and analytical procedures are well documented
(Lioy and Lioy, 2001; OSHA, 1993; NIOSH,1994a).
L4.2 Dermal Exposure Assessment
A range of dermal sampling methods has been described (Ness, 1991; McArthur,
1992; Fenske, 1993; Ness, 1994), but these are generally considered semi-
quantitative.
Surface Monitoring
Surface monitoring, including vacuuming of surfaces, may serve to indicate the
potential for dermal exposure to chemicals. It is, however, an indirect measure and
relies on an understanding of skin contact time and transfer efficiency.
Surface monitoring for radioactive contamination has been widely used for decades,
but has been relatively uncommon for general chemicals (Fenske, 1993).
In some cases, surface monitoring data can display good correlations with reported
syrnptoms, e.g. surface monitoring of deposited glass fibres may be better correlated
with reported dermatitis than air monitoring (Ness, 1994).
An important application of surface monitoring is in respect to demonstrating the
adequacy of work practices, housekeeping and cleanup procedures. Thus, a number of
surface contamination standards have been developed, e.g. 0.2 mg/100 cm' for
sodium fluoroacetate (LaGoy et al., 1992).
Fenske (1993) has highligþted several complications. For example, the reliability of
surface wipe sampling depends on surface characteristics, contaminant loading,
sampling media, and procedures.
8
Skin Wiping
Skin wiping is a convenient method of assessing dermal exposure.
Whatman Smear Tabs were used by Smith et al. (1982) for polychlorinated biphenyls
(PCB) and by Wolff ¿r al. (1989) for polycylic aromatic hydrocarbons (PAH).
Different types of prepacked hand wipes (i.e. Wash 'n' Dri Soft Cloths, Moist
Toweletters, Washkin's Hospital Packettes, Walgreen's Brand Wet Wipes, Lehn and
Fink's Wet Ones and Baby Size 'Wet Ones) have been evaluated (Que Hee et al.,
1985). In the study of lead contamination, the effectiveness of wiping depends not
only on the type of wipe, but also on the number of repetitive wipes. Commercial
paper towel premoistened with benzalkonium and alcohol were used for wiping
hands, fingers and palms at a battery plant (Chavalitnitikul et a1.,1984). Commercial
baby wipes have also been used for skin wiping (NIOSH, 1992).
Groth et al., (1992) used wipers with polyethylene glycol (PEG) for methylene
dianiline (MDA), because MDA is soluble in PEG and PEG is soluble in water.
However, skin cleaning should be conducted prior to wiping, because there may be
pre-existing chemical residues in the layers of the skin (i.e. stratum corneum). Such
pre-contamination should not be removed by waterless cleaners containing lanolin, or
abrasive cleansers. In addition, skin barrier cream should not be used on the day of
sampling, because it may contain lanolin resulting in the acceleration of the
penetration of contaminants (Ness, 1994). Skin wipes may not collect all
contaminants deposited, because contaminants can penetrate into the epidermis during
exposure (McArthur,1992). Volatile components may also evaporate from the skin
surface.
Wiping with solvents may pose a risk to the worker, especially during time-
consuming wiping activities associated with fingers and fingernails.
Skin wiping is not operator independent, and can vary with skin characteristics.
Wiping has been reported to underestimate exposure, compared with hand washing
and a glove method (Fenske et al., 2000). However, much better recoveries were
found in another study when isopropanol was used as the solvent instead of a water-
surfactant mixture (Geno et a1.,1996).
9
Overall, skin surface contamination assessment is problematic and better
methodologies are required (Fenske, 1990; Schröder et a1.,1999; Liu et al., 2000).
Skin Washing
Skin washing is one of the most common removal methods. This method has been
used for washing the hand, wrist, arm, foot and ankle. However, this method cannot
be used for pesticides which have high rates of dermal absorption. The hand washing
procedure has been standardized (EPA, 1986).
Durham and Wolfe (1962) used polyethylene bags and this was more reliable than the
swab method. However, physical characteristics of chemical substances should be
considered, such as whether they are soluble or degraded by solvents (Davis, 1980).
Durham and Wolfe (1962) reported that the recovery rates of parathion from the hand
were JJo/o - 94% for the first rinse, 89% - 98Yo for the second rinse and less than 5%
for the third rinse. They recommendçd three rinses to reach a high efficiency.
The efficiency range for chloropyrifos using water-alcohol mixtures was 23Yo to 960/o
(median 73%) (B.rovweÍ et a1.,2000a).
The Cup Method, being a modified aerosol spray delivery system, has been used
(Keenan and Cole, 1982).'When the actuator button is pressed, the propellant is
sprayed onto the surface of the skin and the rinse liquid from the contaminated skin
surface is collected in a bottle. It has been suggested (Ness, 1994) that this method
would provide more accurate results compared with hand washing or skin wiping.
The Pouring Method is essentially a hand wash involving a stream of solvent (Keenan
and Cole, 1982; Davis et al., 1983; Kangas et al., 1993; Knaak et aL, 1986). Even
though this method is not standardized, it can provide faster sampling collection than
the bag method (Ness, 1994).
Washing techniques are not easily applicable to the assessment of total body exposure
(Brouwer et al.2000a), as they may affect the integrity of the skin, and may provide
an underestimation, e.g. in the case of pesticides.
Removal efficiency should be studied as a part of quality assurance (Fenske & Lu,
1994; Brouwer et a1.,2000a) with a number of variables, such as the field conditions,
10
exposure patterns, relevant time of residence of the contaminant on the skin and
relevant levels ofskin loading present.
Adhesive Methods and Tape Stripping
As a surface sampling technique, adhesives have been used to measure skin
contamination by solid substances. Lepow et al (1975) measured the exposure levels
of lead from contaminated soil on the palms of children using preweighted self-
adhesive labels.
In order to collect fibres causing itching and localized rashes in a data processing
computer room, transparent tape was used on the skin (NIOSH, 1984a). Wheeler and
Stancliffe (1998) used adhesive tapes (e.g., Scotch Tape@ and forensic tape) and
demonstrated that this technique had more efficiency for solids than wipe sampling.
It is a useful assessment method for the determination of the amount and distribution
of chemicals in the stratum corneum (Dick et al., 1997; Nylander-French, 2000). The
chemical concentration profile within the layers decreases with the increase in tape
stripping application (ECVAM, 1999).In a recent study, tape stripping was used to
assess dermal exposure during aircraft. maintenance. Naphthalene was used as a
marker for JP-8 (Chao and Nylander-French, 2004).
Fluorescence
Some compounds are naturally fluorescent, e.g. polycyclic aromatic hydrocarbons,
and the extent of surface and skin contamination can be assessed with a hand held UV
light in a dark room.
Brouwer et al (1999, 2000b) studied dermal exposure from contaminated surfaces by
using fluorescent tracers. A Fluorescent Interactive Video Exposure System (FIVES)
was introduced by Roff (1997) and Cherrie et al (2000). By using fluorescent tracers,
they were able to identify primary and secondary sources of contamination.
The method, however, is costly and has not been widely used.
11
Skin Patches, Pads and Clothing
Simple methods involving pads, patches and clothing have been used to measure the
potential for dermal exposure, e.g. from residue transfer or aerosol deposition.
In assessing the deposition of pesticides on the skin, Fenske (1990) used surgical
Eauze patches. Charcoal cloth was used by Cohen and Popendorf (1989) to measure
potential dermal exposure to a range of solvents.
It is a useful approach in judging the effectiveness of personal protective clothing
against chemicals, and in the determination of where the main exposure occurs on the
body.
As a direct detection method in worþlaces using isocyanates, Permea-TecrM Pads
were used by Rowell et al. (1997) to evaluate the exposure of the skin under
protective gloves.
Skin patch sampling usually only addresses a small section of the body (Soutar et al.,
2000). Therefore, the results should be interpreted with care. Furthermore, the
characteristics of skin patches differ from skin, e.g. when the skin is sweating,
wrinkling and calloused. Adsorption and absorption of chemicals should be
considered (Dost, 1995), and the collection efficiency of the sampling medium should
be determined before collecting samples.
Gloves and socks are complementary to patches and pads, and, like them, may
overestimate the potential for exposure due to absorptive properties (Fenske et al.,
1989; Fenske et a1.,2000; Soutar et a1.,2000).
However, in some tasks, the gloves may interfere with normal work and
underestimation has also been reported (Zweig et a1.,1985).
Protocols have been developed for the estimation of total dermal exposure, e.g. based
on patches or the use of overalls (WHO, 1986; Chester, 1995). Cattani et al., (2001)
used data from overalls, patches and gloves to assess total potential dermal exposure
for workers using chlorpyrifos in termite control.
T2
Dermal Exposure Assessment Toolkits and Models
A Dermal Exposure lssessment Method (DREAM) was developed by Van-Wendel-
De-Joode et al., (2003) and provides a systemic description of dermal exposure
pathways and a guide to the most appropriate measurement strategies.
This semi-quantitative method considers company, department, agent, job, task,
exposure route, exposure module, exposure status, physical and chemical
characteristics, exposure part and protective condition.
Dermal risk assessment toolkits have been developed (Schuhmacher-Wolzi et al.,
2003; Oppl et al., 2003, Warren et a1.,2003). The toolkits consider the hazardous
properties of the chemical in use, exposure conditions, and control status to assess
dermal risks in workplaces. However, input data are not always reliable (Marquart et
a1.,2003; Van Hemmen et a1.,2003).
In order to address these issues, exposure surveys have recently been conducted
(Hughson and Aitken,2004; Kromhout et a1.,2004; Rajan-Sithamparanadarajah et al.,
2004).
Other approaches have been used:
The European Predictive Operator Exposure Model, known as EUROPOEM has been
developed for operator exposure assessment in pesticide application work (NOHSC,
l99l). Like DREAM, the assessor's expertise is an important consideration. A
Pesticide Handlers Exposure Database (PHED) has been used in the US and Canada
(PHED, t992)
The knowledge-based EASE model (Estimation and Assessment of Substance
Exposure) was designed for assessing exposure to new and existing chemicals in the
European Union. The model ranks the worþlaces in broad bands of exposure, and,
therefore, it always assumes homogeneous exposure within the worþlace
(Vermeulen et al., 2002).
1.4.3 Ocular Exposure Assessment
Possible sampling approaches include wiping around the eye or washing the eye
surface. An indirect approach might entail measuring the level of surface
contamination inside or outside eye protective devices.
13
However, there did not appear to be any published literature on ocular exposure
assessment methods.
1 .4.4 Biological Exposure Assessment
Biological monitoring (BM) is used to assess the amount of chemical that an
individual has been exposed to by all routes - inhalation, ingestion and skin
absorption. The objective of BM is to prevent excessive exposure to chemicals, and is
complementary to ambient methods, e.g. air and surface sampling (Lauwerys and
Bernard, 1985; Ho and Dillon 1987; Bernard and Lauwerys, 1989)
BM can sometimes be used to evaluate the contribution from non-occupational
sources, or to perform a retrospective evaluation ofexposure.
There are various BM techniques available for looking at chemical exposure,
particularly for those workers wearing personal protective clothing or for those doing
strenuous physical activities, or working under hot conditions and so on.
The significance of BM in the context of dermal exposure assessment has been
discussed by Fenske (1993). For example, correlations between data from patch
samples with those from urine samples. However, BM does not provide information
on exposure routes or body locations of exposure. Therefore, the amount of
contamination on skin surfaces should be determined (McArthur,1992).
1.4.5 Evaluation of Chemical Protective Clothing
There are numerous methods for evaluating the performance of chemical protective
clothing (NIOSH 1990). For the purpose of this thesis, discussion will be restricted to
gloves and, in particular, methods for the determination of permeation resistance.
Glove Testing
Several standard test methods for permeation have been introduced, e.g. the American
Society for Testing and Materials (ASTM) F139 (1986, 1996) and European
Committee for Standardization (EN) 374 (1994) methods.
Cells for permeation testing are commercially available.
t4
In Australia, Bromwich (1993) developed a simple test cell for chemical protective
clothing, yielding improved assembly time, flexibility, response time and cost.
AS/1.{ZS 2167 part 10.3-2002 for the determination of resistance to permeation by
chemicals has been adapted from the European (CEN) Standard EN 374-3:1994.
Mäkelä et al (2003a) made a comparison of the two standard methods (ASTM F739
and EN 374). However, there was no statistical difference between ASTM F139 and
EN 374 when a gaseous collection medium was used.
1.5 Selection of Chemicals and Processes
1.5.1 Industrial Processes where Skin and Eye Exposure is Likely
There are a number of situations where significant dermal and ocular exposure can
occur, for example manual cleaning and dipping processes, chemical transfer and
mixing, particularly in confined spaces (Warren et aL,2003)
The eyes are of particular concern, as ocular exposure can occur via splashing,
rubbing of contaminated hands on eyes or direct absotption from atmosphere.
The spray application of substances probably represents an extreme case since there is
a deliberate generation of airborne particles that can potentially be inhaled or
deposited on the skin or eyes.
1.5.2 Modeling of Skin and Eye Exposure during Spray Application
Various protocols and models of dermal exposure have been developed (Spear et al.,
l91l; Fenske et al., 1986a, 1986b) and these have commonly been applied to
pesticide workers (NOHSC, 7997; Cattani et aL.,2001).
However, it has only been recently that a conceptual model has been developed
(Schneider et al,1999;2000; Semple, 2004) (see Figure 1 and Table 1).
15
Rds,, +iDs"
II
Rd¡.¡D¡.i,.
Lsu
DPsu
Esu E,qt,.
I
I
J
Cloln,CloOut
Dsr
+ CloIn,Sk
Pst corneum
Ovem&w of iu rnlcq.alal rw&L cæ¡gutttw¿t sd n2!É æn,relrû.E=pnissùm(---), þAryftbn(-|I=rsatspcntùxtor¿tq.otøtlm(----); f=t*r+f"rl-IR=ræaval (---); Fà.=redittùur**t¡ - "' I D=daøttøúnatiæ¿ f --l Pnmctrutj¿natd.pøtmætùm ('--- ).
* Source: Schncider T., Vermeulen R., Brouwer D.H., Cherrie J.W', Kromhout H. and Fogh C.L,, (1999) Conceptual
Model for Assessment of Dermøl Exposure, Occup Environ Med, 56, '156-713.
Figure 1: A Conceptual Model of Dermal Exposure
+Su,CloOut Lcloo,rtl*",oou,,r,, Þp",oou,
I
Est
t--
II
!
I Dpsr
CloOut,Sk
lrruI
I
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I
I
Rst,suI
Rsk,croout
->
I
itIIIIIII
IIIIIII
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I
I
I
I
I
I Rdsr.
AirSurface
contaminantlayer
Source
Outer clothingcontaminant
layer\
I
\
Inner clothingcontaminant
layer
Pcloo,rr,cloLt
P
Rdctoout
Rdctorn
Rsk,clorn
Skin contamination layer
16
Compartment DefÏnition of metric Svmbol Relation Units
Source
Mass of harzardous substance availablefor emission
Concentration of a hazardots substance
in the source
Mg
C5
û
g.g-1, g.m3
Air
Mass of substance in the air compartmentVolume of the air compartmentConcentration of hazardous substance in
the air
M¡.i,V¡,i,C¡,i,
g1m'
-tg.m -
Surfacecontaminationlayer
Mass of hazardous substance in the
surface contamination layerConcentration of a hazardous substance
on the surfaceArea of surface which is contaminated
with hazardous substance
Msu
Csu
Asu
M5"/ (Mr"+Mo*")
2cm
ob
g.kg-r
Outer clothingcontaminantlayer
Mass of hazardous substance in the outerclothing contamination layercompartment
Concentration of a hazardous substance
in the outer clothing compartmentArea of the outer clothing which is
contaminated with hazardous substance
Mcloou,
Ccloou,
Actnoo,
Mcroou,/ (Mctoor,lMo,n"rouJ
û
g.kg-r
2cm
Inner clothingcontaminantlayer
Mass of hazardous substance in the innerclothing contamination layercompartment
Concentration of a hazardous substance
in the inner clothing compartmentArea of the inner clothing which is
contaminated with hazardous substance
Mctolt
Cctoln
Actorn
Mctorn/ (Mcrom*Morl"¡n)
ûb
, -lg.Kg
2cm
Skincontaminationlayer
Mass of hazardous substance on the skinsurface
Concentration of a hazardous substance
in the skin contaminant layerA¡ea of the skin which is contaminatedwith hazardous substance
Msr
Cst
Asr
M5¡/ (Ms¡+M6n")
o
. -lg.Kg
2cm
Table 1: Compartment Descriptors for Conceptual Model
Moher: rnâss of all other substances in a particular compartment
Source: Schrreider T., Vermeulen R., Brouwcr D.H., Cherrie J.W., Kromhout H, and Fogh C.L., (L999) Conceptual Model
for Assessnent of Dernal Exposure, Occup Environ Med, 56, 756-773.
Fundamental predictive models of inhalational exposure in spraying processes have
been developed by Flynn and co-workers, and these have been validated in simple
laboratory-based scenarios (Carlton and Flynn, 1997; Flynn et al., 1999). No such
model exists for dermal exposure, although Semple and coworkers (2001) described a
semi-empirical dermal model for spray painters, and Hughson and Aitken (2004)
reported on dermal exposure results for selected dermal exposure operations (DEO),
including spraying. 'Warren et al (2003) published default dermal exposure values for
risk assessment toolkits. For spraying, the two principal mechanism of exposure were
7l
aerosol deposition on skin, and surface contact, representing exposure via
intermediate contaminated surfaces.
With regard to ocular exposure, there do not appear to be any models, although the
three principal dermal exposure mechanisms may be applicable, i.e. direct contact,
surface contact and aerosol deposition (Warren et a|.,2003). The fundamental models
for inhalational exposure during spraying may be useful in respect of providing input
data for the broader semi-empirical models. However, owing to the complexity of
spraying processes, e.g. object shape, orientation of the sprayer relative to mechanical
ventilation systems, droplet size etc, there is a need to conduct direct measurement in
most situations (Brouwer et a1., 2000b). Processes associated with spraying, such as
mixing and cleanup may represent simpler dermal exposure assessment situations, and
for these tasks the direct contact mechanism, e.g. exposure from splashing, may be
important.
1.5.3 Selection of Chemicals for this Research
Given the potential for the skin and eye exposure in spray processes, it was considered
worthwhile to look at local industries where spray processes occur. Two situations
were selected for this study:
1. The use of organophosphate (OP) pesticides (e.g. malathion and fenthion) in
Mediterranean fruit fl y eradication
2. The use of hexamethylene diisocyanate (HDl)-based aliphatic isocyanates in
automobile repair and furniture industries.
The situations and chemicals were selected due to the availability of populations of
workers, the potential severity of health effects and the lack of specific exposure data
elsewhere (see later).
South Australia (SA) has a large agricultural industr¡ including fruit production
which is potentionally threatended by fruit fly. Periodic infestations have been
eradicated through monitoring and application of OPs.
18
Similarly, SA has alarge number of such small and medium size furniture and motor
vehicle-related industries, where the use of isocyanate-based two-pack spray paints is
common.
OP Pesticides (Malathion; MAL & Fenthion; FEN)
In order to control the Mediteranean fruit fly and protect SA's $250 million
horticultural industry, a standard eradication program has been implemented by
Primary Industries and Resources South Australia (PIRSA, 2001) and involves OP
pesticides, such as malathion (MAL) and fenthion (FEN).
Malathion (diethyl dimethoxythiophosphorylthio) succinate; CAS No. l2l-75-5) is
applied in a protein bait which attracts and kills fruit fly. Fenthion (O,O-dimethyl-O-
4-methylthio-m-toly1 phosphorothioate; CAS No. 55-38-9) is applied to wet all
foliage surfaces of potentially affected fruit trees and shrubs in domestic gardens. For
malathion (MAL) bait spraying, spray workers use a single 14 litre bacþack spray
unit (knapsack) containing MAL diluted in water. Diluted solutions of fenthion are
applied to trees or foliage by using air pressure equipment or a hand pressure spray
gun.
The spray workers typically wear respiratory protective equipment (half-face mask)
and protective clothing (overalls, gauntlets, boots, sunglasses with side-shields and
hats) for in field applications.
Plate 3: Spray Worker Applying Pesticide
l9
During the applications, the spray workers can be contaminated by airborne
fumes/vapors, solution leakage from the knapsack and spray gtn tozzle, and
contaminated surfaces. However, exposure to the chemicals can be reduced by
wearing appropriate PPE. Plate 3 is a photograph of the spray application of fruit fly
bait.
Exposure to such pesticides via dermal absorption, inhalation and ingestion can lead
to adverse health effects, such as dermatitis, irritation, sensitization and systemic
effects. These can be short or long term effects (Reeves et al., 1981; Mahiey et al.,
1982; Albright et al., 1983; Gosselin et al., 1984; Wali et al., 1984; Balaji and
Sasikala, 1993; EPA,200Qa,2000b; PIRSA, 2001; Gin et a1.,2002; Hayes, 7982,
1990; Brunetto, 1992).
Is o cyanate (H examethylene Diis o cyanate ; HDI)
Spray painters are an occupational group at potentially high risk of respiratory and
skin disorders. For example, Ucgun et al (1998) concluded occupational asthma was a
common among automobile and furniture painters.
Isocyanates, usually as oligomers of HDI or isophorone diisocyanate are present in the
hardeners of two-pack polyurethane paints, routinely used in most crash repair
workshops (Mohanu, 1996).
Following mixing of the hardener with paint resin and reducer solvent, the paint
slowly cures, and must be sprayed onto the object, typically within 15-30 minutes.
However, once cured the aliphatic polyurethane coating displays exceptional
durability and resistance to yellowing.
Two-pack spray painting is generally conducted in a spray booth, and usually involves
coloured undercoats and clear top coats.
In crash repair shops using isocyanate-based paints, the main activities are surface
preparation, paint mixing, compressed air-assisted spraying, drying, wet or dry
rubbing, and cleanup. The spray painting is generally accomplished with either a
conventional (higþ-pressure induced venture or gravity feed) or an HVLP (high-
volume low-pressure) spray gun.
20
The spray painters typically wear overalls or disposable coveralls, disposable gloves,
boots, a fuIl face-airline mask or a half face afu purifying mask. They are potentially
exposed to isocyanates from airborne contaminats (dusts, mists or vapors),
contaminated surfaces and clean up proceses. Plate 4 illustrates spray painting with
isocyanates.
Plate 4: Spray Painter Applying Isocyanates
1.6 Organophosphate Pesticides O{AL, FEN) Used for The Control of The
Mediterranean Fruit Fly
This section introduces the specific procedures, toxicology and previous research.
1.6.1 Introduction
Pests are any organisms adversely affecting human interests, e.g. destroying crops,
decreasing harvests and spreading disease. Pesticides such as fumigants, herbicides,
insecticides and rodenticides may be used to control pests (Arnold,1992; EPA, 2001).
Of the pesticides, insecticides are subdivided into inorganic insecticides, chlorinated
hydrocarbons, carbamates, synthetic pyrethroids and other botanicals, and
organophosphates (Dent, l99I).
2T
The widespread use of pesticides has the potential to result in human exposure and
adverse effects. According to Edmiston and Maddy (1987), 2,099 illnesses or injuries
were reported by the Worker Health and Safety Branch of the Califomia Department
of Food and Agriculture in 1986. Around 5l%o were related to pesticide exposure.
Fruit fly are major pests of horticultural crops in Australia (Smith, 1991). They are
generally found hovering near decaying vegetation and overripe fruit as well as in the
home, especially when vegetable or fruit materials are present after major home
canning efforts. Fruit flies target apricots, peaches, nectarines, apples, pears, citrus
and guava. In order to control fruit flies, there are several control methods, including
cover sprays, protein bait sprays, traps, fruit removal and sanitation.
Fruit fly, of which there are over 80 species, were introduced into Australia over fifty
years ago. These include the native Queensland fi:uit fly in the eastern states and the
Mediterranean fruit fly in Western Australia and South Australia. Since 1891, a policy
of fruit fly eradication had been established.
In 1947, the first outbreak of fiuit fly occurred in SA. Several mechanisms were
suggested to control the extent of fruit fly infestation in SA, such as the removal of
fruit from backyards and the disposal of fruit/plant material. At that time, lure traps
and bait spraying were performed to eradicate fruit flies.
Earlier programs used DDT or other organochlorine chemicals that were available at
the time, but DDT was banned in Australia in 1985, due to concerns about
environmental and human toxicity. Since then, the organophosphates have been
applied for pest control in a program of work which is administered and controlled by
the Department of Primary Industries and Resources South Australia (PIRSA).
In SA, fruit fly outbreaks are discovered by a system of vigilant householder reporting
larvae found in fruit and a network of over 3,800 fruit fly trapping sites across the
State. Outbreaks in metropolitan Adelaide are controlled by the imposition of a strict
quarantine upon affected areas, and a control program including the use of the
organophosphorus insecticides (OPs) MAL and FEN.
22
As mentioned, the responsibility for the control and eradication of outbreaks of fruit
fly rests with PIRSA which has legislated authority to enter private premises to apply
insecticides and remove infested fruit (Fruit and Plant Protection Act 1992), although
the co-operation of the community is essential for the effectiveness of the control
program.
In general, when there is an outbreak of fiuit fly, PIRSA establishes two boundaries.
From the outbreak centre, aî area within 200m radius is subject to intensive treatment
using MAl/protein baiting, and insect pheremone traps are used to monitor fruit fly
numbers. Traps are used between 200m and 1.5km to ensure the outbreak does not
spread. The PIRSA officers are empowered to strip and remove all fruit from affected
trees. They then spray all fruit trees and those of all trees within 200 metres as well as
on the ground underneath and set pheromone traps every 1-2 weeks for six weeks.
In 2001, as a consequence of public concems, PIRSA conducted a risk assessment of
potential health effects resulting from exposure to MAL and FEN.
Organophosphate pesticides act through the inhibition of the eîzpe
acetylcholinesterase (AChE) leading to impairment of the nervous system. The
inactivation of AChE can cause the accumulation of acetylcholine at the neuroceptor
transmission site (DHHS, 1993). For instance, OPs cause target species to lose muscle
coordination, convulse and die. Similar enzymes are found in mammals, including
humans, and non-target toxicity is mediated through the same mechanism. The main
symptoms in humans arise from AChE inhibition in the central nervous system (CNS)
and at muscarinic and nicotinic nerve terminals in the periphery. Acute s5rmptoms
include headaches, skin irritation, stomach pains, vomiting, eye irritation and diarrhea.
Possible chronic symptoms include neuropsychological outcomes, peripheral
neuropathy and psychiatric illness (EPA, 2002a).
OP compounds have been investigated for genotoxic effects since they are weak
alkylating agents (Fest and Schmidt, 1913) and have been found to be mutagenic in
bactena(Hanna and Dyer, 1975; Shirasu et al.,1976;Waters et a1.,1980), although in
other test systems, including human cells in vitro and sister chromatid exchanges, a
cytogenetic measure of genotoxicity, results have been inconclusive (Collins, 1972;
Ficsor et al.,l97l; Wild, l9l5; Van Bao et a1.,I974;Hogstedt et a|,,1980; Nicholas
23
and Van Den Berghe,1982). Human exposures in vivo have also yielded both positive
and negative results (WHO, 1986), and these discrepancies may be associated with
studies being poorly controlled with respect to other chemical exposures or variations
in the formulation of pesticide used.
Public concerns about the effect of OPs exposure are related to the possible
consequences of long-term exposure to low levels of OPs. In particular, a range of
non-specific flu-like symptoms and partial paralysis were claimed to be associated
with OP exposure in sheep farmers exposed to OP compounds in insecticidal dips
(Independent, 1992). It is unclear whether these symptoms are manifestations of
chronic OPs exposure at low concentrations or are associated with unreported high
intensity exposures.
Biological monitoring techniques can be applied to workers exposed to OPs in order to
assess the extent of their exposure. This has generally involved the measurement of
peripheral cholinesterase enzymes which are inhibited by OPs, including red blood cell
cholinesterase and serum (plasma) cholinesterase (Gage, 1955; Mason and Lewis,
re3e).
The inhibition of these peripheral enzymes differs from that of those in the central
neryous system but monitoring of the peripherul enzymes is a useful marker of acute
toxicity (70% inhlbition of plasma cholinesterase is generally associated with clinical
effects) (Mutch et al., 1992). Peoples and Knaak (1982) stated that the determination
of plasma and red blood cell cholinesterase is the optimum method for
organophosphate identification. Most organophosphates are readily hydrolyzed by the
liver and as such exert their effect faster, however some of them are stored in the liver
and release slowly therefore delaying its toxicity.
Peripheral lymphocyte neuropathy target esterase (NTE) activity has also been
monitored as an indicator of delayed polyneuropathy (Mutch et a1.,1992; Lotti, 1986).
Other biological monitoring strategies have been developed, including the
measurement of urinary dialkyl phosphates and metabolites of OPs. These estimate the
exposure level of OPs and the relationships between exposure, uptake and response
(Davies et a1.,1979).
24
Recent work has suggested that workers wearing protective equipment exposed to OP
sheep dip at concentrations which altered neither cholinesterase enzyme activities nor
urinary levels of dialkyl phosphates cause significant changes in sister chromatid
exchange frequencies in peripheral lymphocytes (Hatjian et a1.,2000).
MAL is a slightly toxic compound in EPA toxicity class III as a General Use Pesticide
(GUP). The common name is "malathion" with the synonym of 0, O-dimethyl S-(1, 2-
dicarbethoxyethyl) phosphorodithioate. Registered trade names ane Cekumal,
Fyfanon@, Malixol@ and Maltox@ (Howard and Neal, lg92). The chemical formula is
CroHrqOePSz.
H3C
-ç
S
Figure 2: Chemical Structure of Malathion
Figure 2 represents the chemical structure of MAL. Physical and chemical properties
have been reported in several publications (Matsumura, 1985; Howard and Neal,
1992; Budavari, 1 996 CHEMV/ATCH, 2003 a).
FEN is a moderately toxic compound in EPA toxicity class II as a Restricted Use
Pesticide (RUP) due to the special handling warranted by its toxicity. FEN is one of
the OPs used against sucking or biting pests, fruit flies, stem bores, mosquitoes and
intestinal worrns. FEN can be used in dust, emulsifiable concentrate, granular, liquid
concentrate, spray concentrate and wettable powder formulations (Meister, 1992).
CH¡È
ilOP(OCHr)r
Figure 3: Chemical Structure of Fenthion
ÇHCOOCTHsI
CHTCOOCTHsH¡C
-o
CH¡S
25
It is known as a 4-methylmercapto-3-methylphenyl dimethyl thiophosphate, Bay
29493, Baycid, Baytex, Entex, Lebaycid, Mercaptophos, Prentox FEN 4E, Queletox,
S 1152, Spotton, Talodex and Tiguvon. However, FEN has not been one of the
chemical approved by FDA, due to a large number of poisoning deaths. Figure 3
represents the chemical structure of FEN. Physical and chemical properties are
described in many studies (Hayes and Laws, 1990; Meister, 1992; ICSC, 1993;
CHEMWATCH, 2003b).
According to a Ministerial review of the PIRSA fruit fly eradication program (PIRSA,
2001) complaints from the SA public were significantly increased in 2000 and 2001.
However, no specific symptoms were documented and the possibility of adverse
health symptoms caused by exposure to MAL and FEN used for the Mediterranean
fruit fly eradication in SA was thought to be low. Nevertheless, the application of
FEN in cover spraying was temporanly halted following the release of the Report.
I.6.2 Overview of Health Effects
Organophosphorus insecticides generally elicit adverse health effects by inhibiting
acetylcholinesterase (AChE) in the nervous system with subsequent accumulation of
toxic levels of acetylcholine (ACh) as a neurotransmitter. Galloway and Handy (2003)
reviewed the toxicological effects of OPs in terms of immune systems and functions.
Immunotoxicity may be direct via inhibition of serine hydrolases or esterases in
components of the immune system, through oxidative damage to immune organs, or
by modulation of signal transduction pathways controlling immune functions. Indirect
effects include modulation by the nervous system, or chronic effects of altered
metabolism/nutrition on immune organs. Other side effects rvere decreased host
resistance, hypersensitivity and autoimmunity. However, they suggested a selection of
generic biomarkers to provide the evidence of human immunotoxicity.
With MAL, exposure can cause liver and kidney damage, and irritation to mucous
membranes. It also acts as a cholinesterase (ChE) inhibitor and may cause seizure,
26
nausea, vomiting, airway obstruction, blood disorders, cardiovascular system injury,
gastrointestinal disturbances, nervous system injury andlor increased mucous
secretions in the lungs (EPA, 2002b).
Acute effects include the degradation of acetylcholinesterase in the tissues, headaches,
dizziness, weakness, shaking, nausea, stomach cramps, diarrhoea and sweating. There
are no data demonstrating carconogenicity. Chronic exposure can lead to the loss of
appetite, weakness, weight loss and general feeling of sickness (ATSDR, 1998a,
2000; PIRSA, 2002).
FEN may cause seizure, nausea, vomiting, airway obstruction and/or increased
mucous secretions in the lungs (Gosselin ¿/ al., 1984), although chronic exposure
symptoms and acute symptoms are qualitatively the same as with MAL. (PIRSA,
2002).
L .6.2.I Absorption, distribution, metabolism and excretion
MAL
MAL is absorbed by the skin as well as by the respiratory and gastrointestinal tracts.
In an oral animal study, more than 90% of MAL dose was excreted in urine withinT2
hours, with most excretion in the first 24 hours. MAL did not appear in organs or
tissues. The dermal absorption rate for malathion in humans is about 10% (Feldman
and Maibach, 1970; ATSDR, 2000). Dermal absorption depends on skin
characteristics in different exposed areas (Feldman and Maibach, 1974;Ravovsky and
Brown, 1993; Dennis and Lee, 1999).
The major metabolites of malathion are mono- and di-carboxylic acid derivatives, and
malaoxon is a minor metabolite. The principal toxicological effect of malathion is
cholinesterase inhibition, due primarily to malaoxon and to phosphorus thionate
impurities. However, over 80 Yo of the radioactivity in urine was represented by the
diacid (DCA) and monoacid (MCA) metabolites. Only between 4 and 6o/o of tkre
administered dose was converted to malaoxon, the active cholinesterase inhibiting
metabolite of malathion. (Reddy et a|.,1989).
The elimination of a methyl group catalyzed by glutathione S-transferase increases
MAL metabolism (Bhagwat and Ramachandran, T975; Malik and Summer, 1982).
27
Urinary excretion was examined in several studies (Feldman and Maibach, t974;
Ravovsky and Brown, 1993; Dennis and Lee, 1999). Urinary samples provides the
identification of metabolites mostly (Lechner and Abdel-Rahman, 1986).
FEN
Fenthion is moderately toxic if ingested, inhaled, or absorbed through the skin. It is
oxidized to fenthion sulfoxide and the oxon derivative (Kitamura et al., 2003a,
2003b). FEN and its metabolites were found in the fat of steers slaughtered 3 days
after dermal application of fenthion (Hayes and Laws, 1990). FEN was detected from
fat, gonads, kidney, muscle and liver (Puhl & Hurley 1982; Crosby et al., 7990).In
1992, Weber & Ecker reported the similar results in terms of gastrointestinal
absorption.
FEN was excreted from urine and faeces following oral exposure, and a range of
activities were coffelated with urinary output, such as brain acetylcholinesterase
activity, erythrocyte acetylcholinesterase activity (Brady and Arthur 1961; Inukai &
Iyatomi 1981; Puhl & Hurley 1982; Krautter, 1990; Doolottle & Bates, 1993).
I.6.2.2 Mechanism of toxicity
Cholinesterase is one of many important enzymes needed for the proper functioning
of the nervous systems of humans. Stimulating signals are discontinued by a specific
type of cholinesterase enzymq acetylcholinesterase, which breaks down
acetylcholine, ending the signal. If cholinesterase-affecting insecticides are present in
the synapses, however, this situation is thrown out of balance. The presence of
cholinesterase inhibiting chemicals prevents the breakdown of acetylcholine.
Acetylcholine can then build up, causing overstimulation of the nervous system. Thus,
when a person receives to great an exposure to cholinesterase inhibiting compounds,
the body is unable to break down the acetylcholine (DHHS, 1993).
Figure 4 shows the mechanism of action of OPs. When the depression of
cholinesterase is l5-25yo, slight poisoning will be recognized. For moderate poisoning
and severe poisoning, the levels are25-35Yo and35-50o/o respectively. In other words,
28
if the level of cholinesterase in either plasma or RBC has dropped to 30%, the
exposed worker should avoid further exposure (Jane 1987). If exposure to pesticides
ceases, the inhibition of cholinesterase is reversible, and the activity of cholinesterase
will retum to normal. The accumulation of OPs leads a high degree of inhibition and
increased signs of poisoning (Machin and McBride, 1989a, 1989b). In humans, the
inhibition of cholinesterases in RBCs and plasma is associated with signs of
poisoning, such as headaches, blurred vision or vomiting (Moeller and Rider, 1962).
Organophosphates
E:rc es s o f anetylcholine
Health effects
Figure 4: Toxic Mechanism of Organophosphates
L6.2.3 Skin, eye and mucous membrane effects
MAL
There is a shortage of data about skin, eye and mucous membrane symptoms of
humans exposed to MAL.
In animal studies, Relford et al (1989) reported mild dermatitis in mice with brief
whole body immersion in a dip preparation composed of 8% MAL.
Ekin (1971) found pupillary constriction and blurred vision in humans. According to
the study results, the known symptoms were from the stimulation of parasympathetic
autonomic postganglionic nerves, common features of organophosphate poisoning.
Ocular problems were found, e.g. swelling, irritation, blurring, double vision or poor
Lo s s o f ac etylchollnestaas e enzl¡rne
29
vision, mild redness of the periocular tissue and retinal degeneration in general human
subjects and animals (Markowitz et a1.,1986; Dementi, 1993; Daly, 1996).
FEN
Dean et al., (1967) recognized that the signs of acute poisoning by FEN in humans
begins with blurred vision. There is a shortage of data relating to skin and mucous
membrane symptoms following FEN exposure. In animal studies, no dermal
sensitization was observed (Eigenberg, 1987a, 1987b). However, chronic active
inflammation of the skin of the tail and hind limbs was detected (Christenson, 1990a).
I .6.2.4 Respiratory effects
MAL
In animal studies, known symptoms are hyperplasia of the olfactory and larynx
epithelia, dyspnea and respiratory distress which may be caused by the stimulation of
parasympathetic postganglionic nerves or diaphragmatic failure (Prabhakaran et al.,
1993; Beattie, 1994; Piramanayagam et al.,1996).
FEN
From experimental animal studies, FEN exposure is associated with inflammatory
changes of the respiratory tract and correlates with the magnitude of cholinesterase
inhibition aft er dermal administration (Thyssen, I97 8; Christenson, 1 990b).
1.6.2.5 Genotoxicity and cancer
MAL
A range of in vitro and in vivo studies have examined the possibility of genotoxicity
and cancer from FEN exposure. Griffin and Hill (1978) reported abreak of purified
colicinogenic plasmid El DNA from MAL. Sister chromatid exchanges were
observed in human lymphoid cells and lymphocytes, in human fetal fibroblasts, and
Chinese hamster ovary cells (Nicholas et a1.,1979; Nishio and Uyeki, 1981; Sobti ¿r
al., 1982; Balaji and Sasikala, 1993). From in vivo studies, significant numbers of
30
chromosomal aberrations, abnormal metaphases were observed (Dulout et al., 1983;
Dzwonkowska and Hubner, 1986). Balaji and Sasikala (1993) reported that MAL
causes a dose-dependent increase in chromosome aberrations as well as sister
chromatid exchanges in human leukocyte cultures. Thus MAL may contribute to
genotoxicity in humans. In 2002, Giri et al., found significant increases of
chromosome aberrations, sperrn normalities without any affect of a number of sperm
and the significant increase of SCE. They concluded that technical grade MAL may
cause potential genotoxicity and germ cell mutagenesis.
From a human study, Reeves and coworkers (1981) found that blood disorders, acute
lymphoblastic leukemia and aplastic anemia occurred after exposure to MAL. Cabello
et al., (2003) examined the possibility of MAL inducing the progression of malignant
transformation of a human breast epithelial cell line, MCF 7. According to the results,
MAL increased PCNA and induced MCFT and atropine inhibited the effect of such
substances.
FEN
The National Cancer Institute (NCÐ (I979b) indicated FEN as a possible insecticide
of carcinogenicity to male mice, when technical-grade FEN (0-1.0 mglkglday bw)
was fed to rats for 103 weeks. However, no carcinogenic effect to rats and mice was
found in a subsequent repoft (ACGIH, 1986).
1.6.2.6 Other effects
MAL
From a human study, Reeves et al., (1981) found that blood disorders, acute
lymphoblastic leukemia and aplastic anemia occurred after exposure to MAL. There
are other symptoms related to MAL exposure in humans. The development of renal
insufficiency occurred by exposure to MAL (Albright et dl., 1983). With
organophosphate pesticides handlers for over 29 years, there were marked
impairments of neutrophil chemotaxis and significant decrease of neutrophil adhesion
(Hermanowicz and Kossman, 1984).
31
Signif,rcant symptoms were detected, e.g. diarrhoea, constipation or painful bowel
movements, abdominal cramping, diarrhoea, nausea and vomiting (Healy, 1959;
Amos and Hall, 1965; Markowitz et al., 1986). Rupa e/ al., (1991) found that the
percentage of stillbirths and abortions are higher than an unexposed group.
There have been cardiovascular effect studies of MAL poisoning (Rivett and
Potgieter, 1987; Crowley and Johns, 1996).In long-term studies, there is no report of
adverse cardiovascular effects from rats and mice (NCI, I979a; Slauter, 1994).
FEN
There are a rarrge of animal study results for other symptoms, such as decreased
fertility, decreased number of implantation sites per dam, decreased litter size,
increased number of stillborn pups per litter, reduced viability index, decreased pup
body weight, developmental toxicity, increased haemosiderosis, increased body
weight, a slight increase in spleen weight with splenic congestion, extramedullary
haematopoiesis and haemosiderosis, teratogenic effects (Doull et al., I963a, I963b;
Machemer,1978a,1978b; Shepard, 1984; Clemens, 1987; Kowalski, 1987; Kowalski
et a1.,1989; Suberg & Leser, 1990).
In short-term studies, there were decreased activity and ataxia, hlpertrophy or
hyperplasia of the oesophageal glandular components (Hayes and Ramm, 1988;
Hayes, 1989). In a chronic study, no clinical sign of peripheral neuropathy or
myopathy and no pathophysiological findings indicative of arLy reversible
neurological deficits were observed (Misra et a1.,1985, 1988).
1.6.3 Exposure Criteria
MAL
The Acceptable Daily Intake (ADI) of MAL is 0.02 mdkg, and 1 .6 mglday is the
value for 80kg adults. It is based on a No-Observed-Adverse-Effect Levels (NOAEL)
of 0.23 m/k/day. The Lowest-Observed-Adverse-Effect Levels (LOAEL) was 0.34
m/k{day (Moeller and Rider, 1962).
According to Daly (1996), a chronic oral MRL is 0.02 mglk{day. It was based on a
NOAEL of 2 mglkgday for the inhibition of plasma and red blood cell cholinesterase
32
activities in humans. The LOAEL was 29 mglkglday. The Oral Reference Dose
(RfD)was defined with 0.02 mglkglday by IRIS (2001). It was based on 0.23
mglk/day of a NOAEL for the inhibition of plasma and red blood cell cholinesterase
activities in humans and the LOAEL was 0.34 mflkglday.
The TWA Australian occupational exposure standard (OES) is 10 mg/m' iNOHSC,
1995a). The American Conference of Govemmental Industrial Hygienists (ACGIH,
2001) Threshold Limit Value (TLV-TWA) is 10 -dm' with skin notation, based on
cholinergic effects.
Red cell and plasma cholinesterase activity levels are recommended for biological
monitoring of workers using organophosphate pesticides.
There should be a repeat test if there is a 20o/o depression of cholinesterase activity. In
addition, if cholinesterase activity has fallen by 40% or more, the worker should be
moved to the area which is free of the organophosphate pesticides until the level
returns to baseline levels (NOHSC, 1995b).
FEN
The Australian Therapeutic Goods Administration (TGA) has established an ADI for
FEN of 0.002 mglkglday for a 7Ù-year lifetime (PIRSA, 2001). The World Health
Organization ADI is 0.007 mg/kglday.
Several animal studies have assessed acute toxicity levels in terms of oral, dermal and
inhalation (Doull et al., 1961, I963a; Klimmer, 1963, 1971; Mobay Chemical
Corporation, 1981a, 1981b; BCPC, 1983; Meister et al,, 1984; Bailey, 1987,1988;
Suberg & Leser, 1990; NIOSH, 2002).
The TV/A OES is 0.2mg/r; (NOHSC, 1995a). ACGIH recommends the same value
with a skin notation, based on cholinergic effects. There is no carcinogen
classification (PIRSA, 2002; EPA, 2002b).
JJ
1.6.4 Previous Research
The pesticides (MAL and FEN) were examined partly due to concems about
occupational exposure during the Mediterranean fruit fly eradication programs.
In order to understand the risks of adverse health effects, related studies should be
reviewed. However, in the case of MAL few comparable studies have been published.
MAL: Health Effect Assessment
There is a shortage of published literature on adverse health symptoms potentially
caused by MAL exposure during Mediterranean fruit fly eradication programs (Dept.
of Preventive Medicine, 1992; Kahn et a1.,1992; Schanker et al., 1992; Thomas et al.,
7992; MMWR, 1998).
The Department of Preventive Medicine at the University of Southern Califomia
(1992) identified an association between abortion and exposure to MAL, applied to
control the Mediteffanean fruit fly. In this study, 933 pregnancies were surveyed. It
was found that the risk of gastrointestinal disorders in children exposed to MAL
during the second trimester of pregnancy was over two and one-half times more than
for children who are not exposed to MAL during pregnancy. However, there was no
relationship between MAL exposure and adverse health symptoms, such as
spontaneous abortion, intrauterine growth retardation, stillbirth or most categories of
congenital abnormalities.
During the period of the study, no investigation of subtle neurological disorders such
as language delays, attention deficits, learning disabilities, hyperactivity or conduct
disorders was conducted.
Relationships between allergic skin reactions (urticaria, angioedema and nonspecific
skin rash) and immediate or delayed types of hypersensitivity reactions potentially
arising from repeated exposure during MAL baiting were studies by Schanker et al.
(1992). For this study, ten subjects were selected, but only one case represented a
possible immediate IgE reaction to MAL baiting.
Acute health effects from the spray application of MAL bait were assessed by Kahn e/
al. (1992). SelÊreported syn.rptoms from on-site health interviews were headaches
(20.6%), shortness of breath (1.6%), cough (9.7%), watering eyes (13.9%), difficulty
34
breathing (4.2%) and skin rcsh (4.6%). No acute health effects were reported from
the surveillance of hospital data, review of ambulance dispatches and a review of
emergency treatment. In addition, no significant acute morbidity was reported from
personal interviews conducted before and after MAL bait spraying.
Thomas et al., (1992) investigated 7,450 women pregnant during a period of MAL
application. There was no evidence for an association between MAL exposure and
spontaneous abortion, intrauterine growth retardation, stillbirth or congenital
abnormalities. However, a moderate relation between stillbirths and exposure
accumulated up to 1 month before death was found.
A study of potential health effects arising from MAL exposure was conducted in
Florida (MM\ryR, 1998). The public was surveyed via telephone hotlines. Of the 230
calls, 123 individuals were identified as possible cases with adverse health syrnptoms.
Of the l23,l2yo were female (median 46.5 years),7o/owere children (<5 years), 16%
were older people ()65 years) and 3o/" were people whose health syrnptoms could be
related to their work, such as pesticide workers or gardeners.
The following distribution of synptoms was reported:
7l% respiratory (dyspnea, wheezing, coughing and upper respiratory tract
pain and irritation);
63% gastrointestinal (nausea, vomiting, diarrhea, melena and abdominal
cramping);
60Yonewous (headaches, vertigo, ataxia, peripheral paresthesia, disorientation
and confusion);
23o/o sktn (erythema, pruritis and burning sensations);
79o/o oîthe eyes (lacrimation, conjunctivitis, blepharitis and blurred vision).
More than one symptom or experience was reported by some people. It was suggested
the symptoms were likely to be related to MAL exposure, even if only small
quantities of MAL were applied in the eradication program.
35
Taylor (1963) suggested that children under the age of seven are more Sensitive to the
anticholinesterase effect than adults. However, good evidence for this assertion was
lacking.
Biological Monitoring
Biological effect monitoring strategies have been developed, using endpoints related
to genotoxicity. There have been several in vivo studies with humans exposed to MAL
(Van Bao et al., 1974; Titenko-Holland et al., 1997; Singaravelu et al., 1998;
Windham et al., 1998). When an exposed group was compared with an unexposed
Soup, no differences were seen in proliferation ot micronucleus levels in
lymphocytes (Titenko-Holland et al., 1997; Windham et al., 1998). However,
according to Singaravelu et al., (1998), there was a significant difference in chromatid
aberrations, in the case of individuals exposed to MAL for 11-20 years, when
compared with an unexposed goup. These biological effect approaches have
advantages in representing integrated pesticide exposures over weeks to months and
have been shown to be very sensitive markers of exposure (Hatjian et al, 1993).
Exposure Ass essment/[Irork Practices
MAL and FEN exposure levels were reported from several studies (Garcod et al.
1998; Tuomainen et aL.2002; Machera et a1.,2003).
Twenty surveys from 15 sites spraying remedial pesticide were conducted to measure
surface deposition and inhalation exposure levels (Ganod et al., 1998). Coveralls,
protective gloves and socks were surveyed for deposition rates. The applied pressures
were 320 and 1050 kPa. Deposition rates of coveralls were between2l.4 and 6550
mg/minute (209 mglminute-median). On the body, the depositions on the legs, the
arrns, the torso and the head were l5o/o, Ilyo, l2o/o and 2Yo respectively. Beneath
protective gloves, the exposure levels of the hands were betweet 0.2 and 358
mgiminute (5.8 mglminute-median). According to the observation of the authors, skin
contact arose from contaminated surface or outside of the gloves during their removal.
Also, it was thought that the contamination of hands might contribute the
contamination of inside gloves. For inhalation exposure, TWA ranged between 4.33
and 1320 md^3 (53.5 mg/m3-median) in survey.
36
Potential dermal exposure and biomarkers (MAL monocarboxylic acid, MMA).in
urine were measured from pesticide (MAL) applicators (Tuomainen et a1.,2002).The
workers applied MAL to roses in green houses. The urine was collected within 24
hours after starting the application. Dermal monitoring was conducted during the
application as well. Several parts of the body were measured, such as the upper limbs
(I9%), the lower limbs (48%), the hands and chest (30%) and back and head regions
(3%).From the urine samples, small amounts of MMA were detected. Also, the
excretion of MMA was extremely fast at 6-l hours after the application.
From this study, a range of factors influenced exposure, such as working skill,
behavior, time, area and tool (spray gun) and spray volume and density. In addition,
the leaking and spillage of spraying solution from hoses were also observed.
'Whole body dosimetry has been applied to MAL spray applicators to determtne
potential dermal and inhalation exposure levels (Machera et al., 2003). The
proportions of pesticide deposition on the body were 0.05 and 0.07o/o of the applied
spray solution with low-pressure knapsack (3 bar), and 0.09-0.19% of the spray
solution applied with tractor-generated high pressure (18 bar). F-or air monitoring and
hand monitoring, XAD-2 sampling tube and cotton/rubber gloves were used
respectively. It was found that dermal (hands) exposure and inhalation exposure are
related to the application pressure.
FEN: Health Effect Assessment
Several case studies looking at health symptoms associated with FEN exposure have
been published (von Clarmann & Geldmacher-von Mallinkrodt, 1966; Dean et al.,
1967; Wadia et a1.,1977).
Dean et aL, (1967) reported on a man who had taken an unknown quantity of FEN.
He suffered from significant respiratory difficulty, even after 72 hours of emergency
treatment. V/adia et al., (1977) studied patients poisoned by FEN. There was no
pulmonary oedema after FEN poisoning.
FEN is able to irritate eyes and mucous membranes. A FEN formulation was ingested
by a man and adverse symptoms were observed 45 minutes later (von Clarmann &
Geldmacher-von Mallinkrodt, 1966). Cyanotic mucous membranes and no reactions
to pain or light on the pupil were observed with recovery after 8 days of treatment.
37
Biological Monitoring
In order to assess overall exposure levels, biological monitoring can be conducted via
urine and blood samples. Urinary metabolites for OPs and cholinesterase activity can
be monitored. Several researchers have reported biological monitoring data for MAL
(Moeller and Rider, 1962; Wester et al., 1983) and FEN (Elliot & Barnes, 1963;
Taylor, 1963; Pickering, 1966; Fytizas-Danielidou, 1971;Wolf et a1.,1974; Simmon
et al. 1977; Mahiey et al. 1982; Misra et ø1.,1985, 1988; Brunetto et a1.,1992; Cocker
et a|.2002).
Elliot and Barnes (1963) observed that individuals exposed to a high quantity of FEN
used for malaia eradication causes slight plasma cholinesterase depression.
An individual taking 60 g of a FEN formulation called ENTEX @ lOS-lS% pure) was
observed (Pickering, 1966). He suffered from clinical conditions for six days after the
accident. But after the poisoning, the depression of blood cholinesterase activity was
sustained by 22 days. Workers who controlled the mosquito were exposed to FEN via
skin (3.6-12.3 mglh) and inhalation (< 0.02-0.09 mg/h) during chemical application
(Fytizas-Danielidou, Igl l ; V/olf et al., 197 4).
Brunetto et al., (1992) reported the relationship between clinical signs, cholinesterase
activity and FEN levels following oral ingestion of FEN. For this evaluation, plasma
cholinesterase (PChE) activity and FEN concentration were examined during the
therapeutic intervention to determine whether they are predictive of clinical outcome
and the efficacy of treatment. However PChE activity was not suff,rciently predictive
of the likelihood of sudden relapses.
Several OPs including FEN were investigated, with the objectieve of estimating
exposures through the skin (Cocker et al., 2002). Urine and blood samples were
collected and total urinary alkyl phosphates were measured. It was concluded that
urinary alkyl phosphates were more suitable than ChE for occupational and
environmental studies.
38
1.7 HDl-based Isocyanates in Automobile and Furniture Industries
This section introduces specific procedures, toxicology and previous research.
1.7.1 Introduction
Organic isocyanates are compounds containing the isocyanate group (-NCO). They
react with alcohol (hydroxyl) groups to produce polyurethane polyrners, for foams
and paints. Polyurethane products are manufactured for several industries, such as
cars, airplanes, fumiture and bedding.
Table 2: Common Organic Isocyanates Diisocyanates and Physical Characteristics
1) Molecular weight2) Boiling Point3) Commercial TDI is a liquid at room temperature and consists of 2r4 tnd 2,6 isomers in the proportion of 65:35 or,
more commonly 80:20.4) 80:20 mixture5) Beginsto dccompose úa,bout232oC6) At 10 torr.
Common isocyanates used are methylene bisphenyl diisocyanate (MDI), toluene
diisocyanate (TDI), hexamethylene diisocyanate (HDI) and isophorone diisocyanate
(IPDÐ. See Table 2.
Isocyanates, dissolved in aromatic solvents, such as xylene and toluene, are found in
hardeners of two-part paints and primers. Due to the inhalational hazard associated
with monomers, most isocyanates are supplied as oligomers (prepolymers).
Abbreviation Chemical name Formula
TDI Toluene diisocyanate cH3c6H3(NCO)2
MDI Methylene bis (4-phenylisocyanate) OCN-C6H4-CH, -C6H4-OCN
HDI Hexamethylene diisocyanate CrsHrzNzOz
IPDI Isophorone diisocyanate C¡2H1sN202
Isocyanate Appearance MWl) B.PL2)fc)
Vapour pressure(mm Hg)
TDI3)colourless/pale yellow liquid,pungent odour
t74 2s04) 0.02s (2s "c)
MDI brown, viscous liquid orwhite odourless flakes (pure)
250 3t4s) 0.00009 (2s "c)
HDI colourless liquid 168 213 0.05 (25 "C)
IPDI colourless/yellow liquid 222 1586) 0.003 (20 "c)MIC volatile liquid 57 38 348 (20"C)
39
1,6-Hexamethylene diisocyanate (HDI), also known as Mondur HX and Desmodur H,
is a common aliphatic diisocyanate. In HDl-based hardeners, the biuret and
isocyanurate trimers are regularly used. (ATSDR, 1998a; OSHA, 1998). Figure 5
represents the chemical structures of HDl-based polyisocyanates, Physical and
chemical properties are described in many studies (NIOSH, 1978; Lewis, 1993; Von
Burg, 1993;HSDB, 1995).
ocN-(cH2)6-þtco
Hexamethylene Diisocy anate (HDD
OHilt./c-*- (cFI2)6-NCO
ocN-(cHzru-r_r_
ilo
NI
H-(cH2)6-NCO
HDI biuret trimer
NCO
(cHÐc
IN\ ,OC+- -
I
(CHС-NCo
HDI isocyanurate trimer
Figure 5: Chemical structures of HDI and HDI trimers
Approximately 50o/o of HDI prepolymers are biurets containing 0.1-I.6% monomer.
The other 50o/o are isocyanurate trimers containing 0.2Yo monomer. However, even
though high airbome levels of HDI oligomers can occur during spray painting, it is
difficult to determine whether the monomer or pol¡rmer causes adverse health effects
O--*c
I
,N,ocN-(cH2)6/ '1
o
,N
40
(Huynh et al., 1992). At the time of manufacture, monomer content is less than 0.7o/o
based on resin solids. However, after 3-6 months storage, the free monomer content
may rise to a maximum of l.6Yo (EHSD, 2001).
Exposure to HDl-based products is common in spray painters working in the
automobile industry and in furniture manufacture in SA and elsewhere.
An estimated 153,000 auto body repair workers have the potential for sorire exposure
to paint containing HDI in the UK (Meredith et al., 1991). The Motor Trade
Association (MTA) represents over 1,400 businesses in SA. Approximately 20o/" of
these are directly involved with crash repair (Mohanu, 1996).
Automotive refinishing includes autobody repairþaint shops, production autobody
paint shops, new car dealer repairlpaint shops, fleet operator repairþaint shops and
customade car fabication. According to Heitbrink (1995), the major air contaminant
in automobile shops and refinishing industries was polyisocyanates.
In the case of the furniture industry, it was reported that continuous exposure to
isocyanates increased the risk of developing respiratory symptoms for workers in
companies using large quantities of isocyanate-paints (Mastrangelo et al., 1995).
Talini et al. (1998) examined exposed spray painters and unexposed workers
(woodworkers and assemblers). Significant adverse health symptoms were noted for
isocyanate- exposed workers.
1.7.2 Overview of Health Effects
The focus of this subsection is on HDl-based products.
Little information about the toxicokinetics of HDI has been available. HDI can be
hydrolyzed in aqueous media, even if the process is slow. 1,6-hexamethylene diamine
(HDA) is the major urinary metabolite.
According to Tse and Pesce (1979), free HDI may combine with serum proteins.
HDI can have effects on various tissues and organs in the human body. This effect
may occur within a short period of time (acute effect) or over a long period of time by
repeated exposure (chronic effects). According to ATSDR (1998b), known acute
symptoms are likely to be shortness of breath, burning sensation of respiratory
passages, nausea, headaches and increased proneness to accidents. An allergic
4l
respiratory reaction similar to an asthma attack can occur in some individuals with
prolonged or repeated previous exposure or a large single exposure to HDI. Several
respiratory toxicological symptoms were observed with exposures over 0.0006 ppm of
HDI (monomer) (Von Burg, 1993). The observed signs are burning and irritation of
the nose, throat and mucous membranes of the lungs, cough, laryngitis, bronchitis,
tightness of the chest, hoarseness, pulmonary edema, emphysema) cat pulmonale and
asthma-like syndrome. It is known that HDI biuret and trimer can cause respiratory
and immunological reactions which are similar to the HDI monomer in human and
animal studies (Belin et al., 1981; Weyel et al., 1982; Alexandersson e/ al., 1987;
Ferguson et a|.,1987; Usui et al.,1992).
Acute skin contact may cause rashes, blistering and reddening of the skin. Repeated
skin contact may cause skin sensitization. Long term diverse adverse health efects are
possible; kidney and liver dysfunction with possible central nervous system effects,
allergic, asthma, shortness of breath, wheezing, bronchitis, coughing, redness,
irritation and skin damage. Evidence is lacking on carcinogenesis.
Ocular exposure to airborne isocyanates can cause eye irritation and temporary
blurred vision. Direct contact with the eye may cause damage to the cornea.
1.7 .2.1 Absorption, distribution, metabolism and excretion
The main absorption of HDI is by inhalation or skin contact. When inhaled, HDI
binds to human tissues, proteins and DNA, forming adducts which may cause adverse
health effects.
HDI monomer may be metabolízed by hydrolysis to amines excreted from urine
(Berode et al., 1991). Liu et al., (2004) suggested that the metabolism of HDI biuret
aerosol can follow a similar mechanism to that of HDI monomer. However, HDI is
reactive and unstable and high analytical sensitivity is required (Streicher et al.,
2002).
Brorson et al., (1990a) examined the urinary metabolite, 1,6-hexamethylene diamine
(HDA), after oral administration of HDI. The half-life of HDA in urine was between
42
1.1 and 1.4 hours. Brorson et al., (1990b) detected the accumulative excretion of
HDA after acute respiratory exposure. When urinary samples were collected
immediately after the exposure, HDA started to accumulate in urine. In a recent study,
the urinary HDA concentration decreased to the pre-exposure levels 20 hours after
cessation of exposure. (Liu et a|.,2004).
1.7.2.2 Mechanism of toxicity
Even though there is no specific information on the mechanism of toxicity, Karol
(1986) and Von Burg (1993) have suggested that the mechanism is likely to be related
to the reaction with biological macromolecules and various proteins in the body.
I.7 .2.3 Skin, eye and mucous membrane effects
It is well known that isocyanates cause skin irritation and affects mucous membranes.
Hardy and Devine (1979) reported on severe chemical conjunctivitis following
splashes in the eye. Stadler and Karol (1985) found that the greater the dose of HDI,
the more intense of erythema (p < 0.05). Mobay Corporation (198lb) reported severe
congestion, skin thickening, moderate to severe erythema and slight corrosion. Karol
(1986) stated isocyanates may cause contact dermatitis or skin sensitization. However,
skin sensitization may occur as a result from a spill or other accidents. After skin
sensitization, subsequent exposure can cause rash, itching, hives or swelling of the
arms and legs.
Severe eye symptoms were found from animal studies, e.g. lacrimation, a slit-shaped
opacity of the cornea, severe conjuntival inflammation, corneal injury, damage of iris,
moderate corneal injury and iris, inflamed eyelids, moderate eye irritation to the
conjunctiva, and severe damage of the cornea, iris and conjunctiva. (Haskell
Laboratory, 196l; Mobay Corporation, 1966; Mobay Corporation, l98la, 1984,
1e8e).
43
1.1.2.4 Respiratory effects excluding asthma
Inhalation of isocyanates mainly causes respiratory effects, such as chemical
bronchitis with initial symptoms of throat irritation, laryngitis, coughing, and chest
pain or tightness (Phillips and Peters, 1992). A symptomatic change in lung function
was also reported (Musk et a1.,1988).
Symptoms also included mild respiratory distress, marginally decreases body weight,
increasing lung weights, increased recruitment of alveolar marcrophages, focal
interstitial fibrosis with round-cell infiltrations, bronchiolo-aveolar proliferations,
unequivocal changes in respiratory patterns and a bronchial influx of eosinophilic
granulocytes (Pauluhn and Mohr, 2001 Pauluhn et al., 2002). However, HDI-
monomer induced more specific IgG antibody than HDl-homopol¡rmer (Pauluhn e/
a1.,2002).
In short term exposures, acute symptoms were chest tightness, cough, shortness of
breath wheezing, malaise, chill, pulmonary irritation, lung weight, lavage fluid
protein, recover of neutrophils in lavage fluid, proliferative (Belin et a1.,1981; Banks
et aL.,1986; Hagmar et a1.,1987; Vandenplas et a|.,1993; Baur et a1.,1994; Akbar-
Khanzadeh and Riva, 1996; Lee et al., 2003). For longer durations, the Haskell
Laboratory (1961) found bronchitis, bronchopneumonia and also respiratory
impairment with labored breathing and irritation.
Lung function and blood tests implemented by Malo et al., (1983) suggested a
bronchial reaction (decreases in FEVr/FVC ratios as well as a late obstructive and
restrictive breathing defect) after exposure.
l.l .2.5 Occupational asthma
Isocyanates have long been suspected as being causes of occupational asthma.
Meredith et al. (1991) argued that the diisocyanates used in a variety of applications
in many industries can be a main cause of OA. Occupational asthma is induced by
sensitization to variety of substances (Chan-Yeung and Lam, 1986) without specific
mechanisms (Karol, 1988; Kennedy et a1.,1989; Deschamps et a1.,1998).
Isocyanates are cuffently the most common causes of occupational asthma (Park,
1997; Park and Nahm, 1996). Agencies, such as HSE, OSHA and NIOSH, have
44
expressed concem about the potential health risk that may result in workers exposed
to HDI. Piirila et al. (2000) reported on a long-term follow-up study covering the
period 1976-T992. Of 245 new cases of asthma caused by diisocyanates, a high
percentage of cases were induced by HDI (39%) and MDI (39%), with others being
rDr(r1%).
Symptoms may occur within a few days or weeks after exposure to isocyanates and
symptoms or reactions can last several months or years after the end of exposure
(Fabbri and Mapp, 1992).
Deschamps et al (1998) suggest that isocyanate asthma may be induced via several
mechanisms, notably immunological, pharmacological andlor irritative. It is thought
that asthma is multifactorial and there is no general agreement on mechanisms.
In a recent study, Di Stefano et al (2003) studied occupational asthma in
industrialized countries in terms of setum specific IgE to isocyanates. However,
isocyanate-specific IgE could not provide a complete understanding.
It is known that the respiratory tract is the primary route of sensitization. However,
according to recent animal studies, dermal exposure to isocyanates may cause
respiratory sensitization (Karol et al,I98l; Erjefalt and Persson,1992; Rattray et al.,
ree4).
1.7.2.6 Genotoxicity and cancer
There was no evidence of human carcinogenic potential from HDI exposure. Animal
studies have also been negative (Mobay Corporation, 1989).
1.1.2.7 Other effects
In a study by the Haskell Laboratory (1961), very significant respiratory impairment
and cyanosis were observed during exposure. But no changes in blood chemistry,
serum chemistry and hematology were reported (Mobay Corporation, 1988, 1989).
Karol et al., (1984) reported no significant change in plasma cholinesterase by
inhalation.
45
In an intermediate-duration study, decreased kidney weight was observed, and in a
chronic-duration study, no significant change of kidney weight was detected (Mobay
Corporation, 1984,1989). Inflammation of the stomach mucosa, and diarrhoea have
been reported (Haskell Laboratory, 79 61 ; Mobay Corporatio n, 1984, 1 9 8 9).
1.7.3 Exposure Criteria
The National Occupational Health and Safety Commission Occupational Exposure
Standard (NOHSC, 1995a) is designed to prevent respiratory sensitization. The 8-
hour time weighted average (TWA) value for all isocyanates (as -NCO) is 0.02
mg/m3. The 15 minute STEL for all isocyanates (as -NCO) is 0.07 mg/m3. TLV-TWA
is 0.034 mdm3 (ACGIH, 2001).
1,6-Hexamethylene diamine (HDA) is a biomarker of short-term exposure to HDI
(Brorson et al., 1990a,1990b; Dalene et a1.,1990, 1994) but there are no exposure
standards.
1.7.4 Previous Research
For this study, articles were reviewed in terms of ambient monitoring including PPE
monitoring, surveys (health symptoms), biological monitoring and working conditions
(e.g. spraybooth).
Exp o s ur e A s s es s ment /Wo rk P r acti c es
A number of studies provided exposure data and information on protective equipment
usage (Pisaniello and Muriale, 1989a; Janko et al., 1992; Heitbrink et al., 1993a;
Cooper et al.,1993; Cushmac et ø1.,1997;Li:u et a1.,2001b,2004).
Pisaniello and Muriale (1989a) found personal exposures associated with operations
where dusts or aerosols are not generated, such as paint mixing and spray gun
washing, to be very low, typically I pgNCO/m'. No measurements exceeded 2
¡rgNCO/m3, even when sampling directly over open containers of hardener.
46
For the spraying of two-pack (primer/filler)undercoat, breathing zone concentrations
ranged from 7 to 180 pgNCO/m3 ; for solid colours (topcoat), 8 to 3500 pgNCO/m3
and for the spraying of a clearcoat (topcoat), 9 to 550 pgNCO/m3.
In an inhalational exposure study, Heitbrink et al., (1993a) reported exposures
between l7-lg0 pgNCO/m3 using NIOSH Method 5521. Cooper et al., (1993)
reported on control technologies for autobody repair and painting shops. In the case of
small painting tasks, spray booth air velocities were often too low to control air
contamination. Also, inappropriate usage and knowledge of respiratory protection was
observed.
Cushmac et al., (1997) reported the usage of respiratory protection. Full face air and
half face air purifying respirators with organic vapor cartridges and pre-filters for
mists, were not used appropriately. They were not maintained properly or were kept in
poor storage conditions.
From the study conducted by Janko et al., (1992),0.001 ppm of HDI monomer (GM)
and 0.7-12.2 mglm3 of HDI polyisocyanate (GM 3.8 mg/m3) were measured from
spray painting in an industrial spray operation. In autobody shops, HDI monomer
(GM) and HDI polyisocyanates (GM) were 0.014 mdm3 and I.67 mg/m3 respectively.
Liu et al., (2004), using the Isocheck treated-filter method for HDI biuret aerosol,
reported exposure levels (GM) for monomer, oligomers and total reactive isocyanate
group of 53.8 þúm3,98.7 pglm3 and 58.2 pgNCO/m3 respectively.
Liu et al., (2001b) reported on quantitative levels of surface contamination and skin
contamination in autobody shops, and the effectiveness of PPE. From 20 shops, high
contamination levels of surface were measured from hardener containers (2.9-108.1
Itg/inz), bench top (0.8-25 .9 ¡tglir?), rulers (0.5-6.3 Velin2) and gloves (0.11-4.7
IrdirÔ.From the skin, the average exposure levels of monomer and oligomer were
0.3L2.9 pdin2 and 0.01+3 .1 ¡tg/in2 respectively. Under PPE, levels of 0.5+2.3 pdin'
were found, suggesting inadequate protection. In addition, they concluded that due to
painting activity in auto body shops, surface contamination and skin exposure to
isocyanates is common, and that skin exposure can contribute significantly to total
isocyanate exposure can.
47
Health Effect As s es sment
Symptoms were reported in several studies (Alexandersson e/ a|.,1987, Pisaniello and
Muriale, 1989a,1989b; Torniling et ø1.,1990; Parker et a1.,1991; Usui et a1.,1992;
Mastrangelo et al., 19951' Randolph et al., 1997; Ucgm et al., 1998; Talini et
a|.,1998).
Alexandersson ¿/ al., (1987) observed respiratory symptoms. Significant difference
was observed compared with controls (n:70). From the study, it was argued that peak
exposures to isocyanate (HDI) might better relate to respiratory disease than 8-hour
averages. However, no statistical significant spirometric change was obseryed during
a week. Tornling et al., (1990) conducted a followup study with similar conclusions.
A survey of isocyanates exposures in workshops was conducted in SA (Pisaniello and
Muriale, 1989a). From the survey, respiratory and skin problems (cough, phlegm,
short of breath, chest tightness and skin irritation or dermatitis) were found to be
common among spray painters. The prevalences differed significantly from
mechanics not exposed isocyanates.
From this survey work, poor work practices and inadequate personal respiratory
protection were observed. Also, the lack of educational programs for employees and
the difficulty of applying regulations to small business were evident (Pisaniello and
Muriale, 1989b).
Mastrangelo et al., (1995) surveyed furniture workers in the Veneto region of Italy.
From the survey, it was reported that the risk of the development of occupational
asthma could be increased by continuous exposure to isocyanates. Ucgun et al.,
(1998) also surveyed the prevalence of occupation asthma among automobile and
fumiture spray painters in Turkey. They reported similar results.
ln 1997, the respiratory health status and dermatitis among spray painters using HDI
products were reported in a cross-sectional study (Randolph et al., 1997). Chronic
respiratory symptoms, cough, wheeze and wheeze with breathlessness were reported.
Eye imitation (55%) and dermatitis of the hand (32%) were also reported, due to poor
ventilation systems and PPE usage.
In 1998, Talini et al., published a study investigating respiratory syrnptoms, asthma,
atopy and bronchial responsiveness. For spray painters, the prevalence of attacks of
shortness of breath with wheezing, dyspnoea and asthma-like symptoms plus non-
48
specific bronchial hyperreactivity were 13.5% (woodworkers'. 7.7%o, assemblers:
1.6yo), Il.5% (woodworkers: 6.3Yo, assemblers: I.6%) and 13.3o/o (woodworkers:
100/o, assemblers: 4Yo) respectively. Also, a high prevalence of chronic cough, and
wheeze were repofted from spray painters. In this study, atopic spray painters were
deemed to be at higher risk of OA than other workers.
Biological Monitoring
Biological monitoring data have been reported for spray painters using HDI products
(Tinnerberg et al. 1995; 'Williams et al., 1999; Liu et al. 2000, 2001a Ptedlich et al.
200I, 2002; Wisnewski et al., 2003 ; Liu et al., 200I a, 2004).
Williams et al., (1999) detected urinary HDA from 4 spray painters out of 22 workers
working in motor vehicle repair shops. However, no HDA was found in the urinary
samples of unexposed subjects. They concluded that exposure could occur even if the
spray painters wore protective equipment and used appropriate extraction systems.
Interestingly, HDA was measured in the urine of a bystander, when spraying was
conducted out of the booth.
Liu et al., (2001a) studied urinary HDA as a biomarker of HDI from 10 small
autobody shops. In the case of some of workers exposed to 0.17 mdm3 HDI, the
maximum urinary HDA level was 27 pùg creatinine. The measured average levels of
HDA of spray painters, technical repairs and administrative workers were 1.44 pdg,
1.3 þdg and 0.88 pglg respectively. As a result of this study, latex gloves were not
recommended for spray painters using isocyanate (HDD.
Two studies were conducted by Redlich et al., (2001, 2002).In 2001, a cross sectional
study was conducted with 75 subjects. Two major observations were made for
exposed workers, i.e. HDl-specific lymphocyte proliferation (30%) and HDl-specific
IgG Qa%\ Although there was no relationship between asthma and HDl-specific IgE,
there was an increase in methacholine responsiveness, HDl-specific lymphocyte
proliferation, chest tightness and shortness of breath for the group exposed to HDI. In
this study, it was suggested that subclinical diisocyanate asthma may be not easy to
identiff using conventional screening and diagnostic modalities.
49
In the one-year follow-up study (2002),34 subjects staying at the same shops and 11
subjects who had left the shops were observed. There were significant differences,
e.g. a history of asthma - 23 vs. 3% (P < 0.05), bronchial hyper-responsiveness - 23
vs.9Yo, HDl-specific IgG - 64 vs. 29% (P < 0.05), and HDl-specific proliferation-S.I.
2.0 vs. 1.3 (P < 0.05). In this follow-up study, there were no statistically significant
changes in physiology, and immunologic responses.
Wisnewski et al., (2003) conducted the first study of immune response to HDI
exposure in automobile body industry. Blood samples were collected from exposed
workers and an unexposed group. For the exposed Broup, increased proliferation of
specific cell types was detected. They were expressed by unique oligoclonal
gamma/delta T-cells. It appears from this study that HDI can selectively stimulate
gamma/delta T cells which potentially modulate the human immune response to
exposure.
In a human study to assess respiratory exposure to HDI aerosol, urinary hexane
diamine (HDA) was used (Liu et a1.,2004). The samples were collected from spray
workers at 23 autobody shops producing HDI biuret aerosol and vapor. Before the
urinary monitoring, baseline samples were collected. From the subjects, urinary
samples were collected immediately post exposure and every four to five hours up to
20 hours post exposure. Baseline HDA concentrations were between 0.2 p"!g and
M.6 þglg creatinine (GM; 0.7 pdÐ. From the samples collected post-exposure, the
range of HDA concentrations were between 0.a púg and 101 pglg creatinine.
The timing of the urine collection was important in the measurement of urinary HDA
levels. Urine samples should be collected immediately post exposure. They suggested
that HDA may be more indicative of HDI monomer than oligomers. More studies of
HDI metabolism and individual variability in urinary HDA levels were recommended.
Control
In order to minimize exposure to isocyanate (HDI) during Z-pack spray painting, there
is a significant reliance on spray booths (Heitbrink et al., 1993b, 1995, 1996; Woskie
et a1.,2004)
50
Six autobody shops were examined by Heitbrink et al., (1995). In the spray booth,
overspray concentrations were measured within spray painters' breathing zone in
different spray booths (downdraft booths, semi-downdraft booths and cross draft
booths).
According to the evaluation, spray booths were often inadequte to control HDI
exposure from overspray. The major air contamination was polyisocyanate.
The extent of spray painter exposure depended on the type of spray painting booth
and the choice of a spray painting gun. Of the three kinds of spray booths, downdraft
booths were most effective (Heitbrink et a|.,1993b).
In the case of spray guns, HVLP spray painting guns was suggested rather than using
conventional guns (Heitbrink et a1.,1996).
In a recent study, the determinants of isocyanate (HDI) exposure were evaluated in a
large survey of painters (n:380) in auto bodyrepair shops (Woskie et a1,,2004).In
this study there were several influence factors, such as shop size, tasks (e.g. mixing,
cleaning sanding and coating), income, spray location, workers position, an air
purifying system (e.g. booth) and spray paint quantity.
The highest level of airborne polyisocyanate was 3119.6 ¡rgNCO/m3 and around 45o/o
of the samples had over 220 ¡rgNCO/m3 from spraying inside the booth. It was found
that there was no difference between using downcraft and semi-downcraft booths in
terms of exposure.
1.8 Purpose of the Study and Research Questions
1.8.1 Purpose of the Study
Exposures can be identified and effectively controlled only as part of a systematic risk
assessment/management program, which may encompass a combination of ambient,
biological and biological effect monitoring strategies.
Ambient monitoring methods allow for the measurement of chemicals in air or on
surfaces (including skin) to which workers aÍe exposed, but provide limited
information about the extent of uptake of these chemicals into workers'bodies.
51
Biological monitoring of chemicals or their metabolites potentially provides this
information but fails to provide any evidence of effects associated with the uptake'
Biological effect monitoring allows an estimate of some biochemical or cytogenetic
response in chemical-exposed workers. It is important to note that these biological
effect endpoints are not measures of disease, but are used as a signal function to
indicate that some biological event has occurred. Ultimately, health questionnaires or
medical monitoring, such as lung or liver function testing, can be used to assess
clinically relevant disease resulting from exposure. Although biological and biological
effect monitoring methods are most predictive of health risk, they are often invasive
and currently only apply to a limited range of chemicals'
consequently, their application in industry has been sparse. Ambient methods are
more practical and acceptable to the workforce'
Significantly, such methods can be easily integrated into effective prevention and
regulatory sYstems.
The sequence of hazardous chemical evaluation options may be considered as
follows:
ambient monitoring (air, sudaces and other media) <> biological monitoring <>
biological effects monitoring <> health effects or medical monitoring
Although chemicals are widely used in worþlaces, relatively few compounds have
been assessed for dermal and/or ocular exposure, and it is not known how many or
what percentage of workers have signif,rcant chemical absorption through the skin or
eyes (Boeniger and Klingner, 2002; Fenske, 1993; Dost, 1996; Schneider et al',2000;
Nylander-French, 2000; Cherrie et a1.,2000). The area is still in its infancy, and many
questions remain unanswered.
There appears to be a shortage of actual exposure data and a need to systematically
develop and validate dermal/ocular exposure assessment methods and models. In the
case of control by PPE, there is a lack of information on the performance and the
effective service life of PPE, e.g. gloves, used to protect against chemical exposure'
In some cases, PPE can exacerbate chemical exposure, for example by occlusion.
52
Boeniger (1991) has suggested that the thumbs and forefingers might be particularly
vulnerable. In the case of the pesticide sprayers, the palm may also be vulnerable.
1.8.2 Research Questions
In Australia, the control of the Mediterranean fruit fly involving the spray application
of malathion and fenthion is only carried out in South Australia. At the
commencement of this study, little or no exposure data were available. This is a
significant shortcoming in the context of health risk assessment.
Occupational asthma is the most common compensable occupational lung disease in
SA and isocyanate exposure is a significant cause (Gun and Langley, 1987; Gun et al,
1996). Owing to its extensive motor vehicle and fumiture industries, South Australia
has a large number of workers exposed to isocyanates, but the only exposure data
relate to inhalation (Pisaniello and Muriale, 1989a). There is a need to better
understand the dermal route as animal data suggest that it may contribute to
respiratory sensitization. Ocular exposufe may also be relevant.
This study seeks to extend knowledge of the extent, and determinants, of dermal and
ocular exposure. It will provide new data relevant to selected industries of
significance in SA.
It is also proposed to conduct research, which may lead to the development of new
dermal/ocular exposure methods and glove performance evaluation opportunities.
Correlations between ambient exposures, biological measures, observed work
practices and health questionnaire data will be used to develop an understanding of
the etiology of chemical related disease. Importantly, this understanding would be of
great value in terms of chemicalhazard control. In the case of isocyanates, this study
will build on local research investigating exposure levels and health status related to
work practices and working conditions (Pisaniello and Muriale, 1989a)
The specific research objectives were as follows:
1. Evaluate dermal exposures, in total and in respect to particular areas of exposed
skin, e.g. hands, and assessment of the opportunities of exposure;
53
2. Evaluate chemical contamination of the eye surface, arising from the spray
application of chemicals ;
3. Determine the prevalence of skin and eye-related syrnptoms, in absolute terms and
in comparison with a control gfoup of unexposed workers;
4. Compare measured exposufes with observed work practice, equipment and control
measures;
5. Evaluate, where feasible, of uptake using biological monitoring methods and
correlation with ambient and dermal measurements;
6. Assess PPE service life, in particular repeated usage of gloves, in actual field use
and in simulated laboratory experiments'
54
CHAPTER 2. DERMAL AND OCULAR EXPOSURE TO
ORGANOPHOSPHATE PESTICIDES USED IN
FRUIT FLY ERADICATION
2.1 Introduction
An introduction to OPs (MAL and FEN) used for the control of Mediterranean fiuit
fly has been given in Section 1.6 of Chapter 1.
For this study, experiments and observations were carried out at two sites (Lenswood
and Thebarton, South Australia). In order to estimate exposure levels to the pesticides
and adverse health symptom prevalences, questionnaire surveys and a range ofsampling methods were applied (see Section 2.3). Glove testing was conducted to
determine glove performance, i.e. breakthrough times and permeation rates. The
results are described in Section2.4.
A simulation field trial was performed at Lenswood in 2001 with the cooperation ofPIRSA. In addition to air sampling, workers were asked to provide urine samples and
blood samples, and dermal and ocular monitoring were conducted with approval ofthe Flinders Clinical Research Ethics Committee.
During a fruit fly outbreak in2003, pest control workers were requested to provide
their PPE (cotton gloves) and skin wipe samples for analysis. Ocular monitoring was
also carried out after finishing the pesticide application. However, no air monitoring
and biological monitoring were conducted because these had been performed as part
of the earlier simulation field trial, and the main focus of this study was work practice
and behaviour.
2.2 Study Populations
The PIRSA Fruit Fly Control Unit is responsible for spraying and other control
operations in South Australia. In July 2001, Mediterranean fruit fly outbreaks were
identified in three zones of the Adelaide metropolitan area. Pesticide application
crews were deployed to apply MAL bait spray and FEN foliar cover spray to control
ftuit fly (Plate 5). As a result of public concerns about suburban pesticide use, and
55
concems from workers regarding the extent of their pesticide exposure, PIRSA was
asked to conduct a formal risk assessment relating to potential health effects resulting
from exposure to organophosphates (OPs) pesticides (MAL and FEN) while spraying
in the field.
Plate 5: Pesticides (MAL and FEN) Application During Simulation in 2001
Two opportunities were presented to collect data relevant to the risk assessment - A
field simulation of OP applications in a PIRSA orchard in Lenswood in 2001 and an
active OP spray program to control a fruit fly outbreak in metropolitan Adelaide in
April2003 (Plate 6).
Plate 6: Pesticide (MAL) Application During an Outbreak in 2003
56
2.2.1Study Group 1 (Field Simulation Trial, 2001)
The fruit fly pest controllers were recruited through PIRSA, which provided the
author permission to meet the workers and observe work practices. Exposures
associated with the normal spraying process were simulated at the PIRSA field station
at Lenswood, an Adelaide Hills location, in October 200I. For the assessment, a total
of six volunteers were selected by PIRSA. They were all experienced pesticide
sprayers. Three workers were selected to apply MAL baiting and another three
sprayers were selected for FEN cover spraying. In the case of FEN cover spraying, a
single motorized unit containing a diluted solution was used in the field. The area of
bait spraying was approximately 25 m2.
Technical grade MAL and FEN were used for spraying. To prepare for baiting
operations, a team manager transferred concentrate of technical grade MAL and FEN
from 25 L storage drums into a 5 L container, and this concentrate was provided to a
group leader. When the team manager transferred the concentrate, he wore a half-face
respirator fitted with organic vapor and particulate cartridges and protective gloves
(Protector Saf"ty cotton lined PVC protective gloves Cat No. IDDI4), which were
provided to the applicators as well.
With 5 L of technical grade pesticide, a group leader made working strengths solution
using water. Technical grade MAL (58% purity) was diluted with water for spraying
onto trees. The diluted MAL solution (1g in 100 ml in water) was applied (100 ml per
tree). With technical grade FEN (55% purity) solution, the dilution was 0.05% (0.059
in 100 ml in water). Two percent vegetable protein extract was added for fruit fly
attraction. While he diluted the concentrate in a 150 L container, he wore protective
gloves.
The group leader transferred the diluted baiting solution into each knapsack (14 L) for
each applicator. On average, the diluted solution was sprayed for 15 minutes.
Workers lvore personal protective equipment such as overalls, goggles, cotton gloves,
PVC gloves, half-face respirator with organic vapour and particulate cartridges, safety
boots, socks and hat.
51
2.2.2 Study Group 2 (Fieldwork During Fruit Fly Outbreak, 2003)
As a result of an outbreak in April 2003, a two-week MAL baiting program was
undertaken at Thebarton, an inner western suburb of Adelaide.
MAL bait spraying was conducted in teams, comprising one person for baiting
application, one for door knocking and providing information and the team leader.
Baiting sprayers used a knapsack and a spray gun. The capacity of the knapsack was
14 litres and approximately 12 litres of diluted solution was added for baiting each
time. After a knapsack was filled by a team leader, each sprayer wore their knapsack
on the back and sprayed the diluted solution using a spray gun operated by a piston.
The diluted solution (1g of technical grade MAL in 100 ml in water, 2o/o vegetable
protein extract) was applied onto foliage, about 100 ml to each tree and bush. The
application of spray baiting was carried out for approximately 3.5 hours per day for
each sprayer.
Workers wore personal protective equipment such as overalls, shoes or boots,
goggles, hat, cotton gloves underneath PVC gloves, and a half-face respirator with
organic vapour and particulate cartridges.
2.3 Methods
2.3. 1 Fieldwork Methods
For the fruit fly pesticide applicators, aÍaîge of methods were used:
Health and work practice questionnaire, personal air samples, ocular sampling, skin
wipes, skin patches, PPE samples (gloves, socks, hats and overalls), urine þre- and
post-task) and blood þost-task).
2.3.1.1Questionnaire survey (Study Group 2 only)
2. 3. I . 1. 1 Development and pilot investigation
A small cross-sectional health study was conducted as part of the 2003 investigation.
For this pu{pose a questionnaire (Appendix 2.1) was developed to assess the
prevalence of symptoms potentially related to the use of OPs (Cattani et al, 2001), and
58
to obtain information on work practices and experiences. It was piloted with a goup
of several PIRSA and University staff, not involved with the fruit fly outbreak.
A total of 27 male pest controllers were recruited by PIRSA for the two-week MALbaiting program. All agreed to participate in the survey and were privately
interviewed with the questionnaire at the PIRSA depot, at the end of the two-week
period of work. The vast majority of workers had prior experience in fruit fly control,
but there had not been an outbreak in the previous 12 months.
An information sheet (Appendix 1.1), consent form (Appendix 1.3) and complaint
form (Appendix 1.4) were provided and the project was explained by a member of the
research team. The questionnaire included personal information (name, date of birth,
sex, worþlace, job title, work experience and educational status), health information
(respiratory symptoms, skin s¡rmptoms, ocular syrnptoms, other unusual symptoms
and smoking habit) and work practices (chemical usage and PPE usage).
A separate questionnaire was used to assess glove usage (see Appendix2.4).
A control group of 91 unexposed male workers was used. The questionnaire for the
control group included personal infotmation (name, date of birth, sex, worþlace, job
title, duties, working period and outside spending), health information (skin
symptoms, ocular symptoms, other unusual sSimptoms and smoking status) and
chemical usage and work practices (chemical usage and PPE usage) (see Appendix
2.3). The control group was comparable with the pest control applicators in terms ofsocioeconomic status. Unexposed workers were recruited from blue-collar categories,
such as maintenance and manufacturing.
2.3.1.1.2 Administration and human ethics
Details of the proposed study were provided to Human Ethics Committees, and the
study was approved by the Human Research Ethics Committees of Flinders
University (2001) and The University of Adelaide (2003). Notifications of the
approvals were provided by letter in July 2001 (see Appendix 3.1) and in March, 2003
(see Appendix3.2).
No workers actively spraying at the time of the study were excluded.
s9
2. 3. 1. 1. 3 Data analysis
Personal information was kept secure and confidential. Only members of the study
team had access the information. Data from the questionnaires and worksite
observation forms were kept in a locked filing cabinet. Data from the questionnaires
were entered into an Excel spreadsheet, and all information was coded. Names were
removed from the entered data. Data files were kept on a computer requiring
password access, or on floppy disks/CDROMs stored in a locked cupboard. Statistical
analysis was performed by using Microsoft EXCEL on a personal computer.
Reporting of statistics was in summary form with no individuals identified. A two
tailed test of differences of proportions was used (Fleiss, 1981).
2.3.I .2 Worksite observations
From Schneider et al (1999), dermal exposure can be from emission, deposition,
transfer. Work practices, including the use of PPE, were observed and noted during
the 2001 field simulation and 2003 outbreak baiting program. General observations
were conducted for work procedures, the working environment, chemical exposure
source, area of contamination on the body, exposure state, cleaning procedures and
the use of PPE.
2.3 .I .3 Environmental measurements
2.3.1.3.1 Air monitoring (Study Group I only)
PlateT: OVS- Sampling Tube for Air Monitoring of Pesticide'Workers
60
Personal air monitoring for MAL and FEN was conducted at Lenswood in 2001 using
OSHA Versatile Sampler (OVS) tubes
(a combined glass filter/XAD-2 sorbent system) connected to calibrated battery-
powered air sampling pumps.
Plate 7 shows the air monitoring setup. The flow rate of the sampling pump was 1.5
L/minute and was checked before and after sampling with a calibrated rotameter. A
thermoanemometer (DSE Q1411) and portable weather station were used to record
both wind speed and temperature during the field simulation. (Model Number 102083,
Climatronics Corporation, Bohemia, NY), fsupplied by MEA instruments;
Datalogging was with a Unidata Australia Starlogger Model 6004C1.
As soon as sample collection was finished, each collected sample was stored in a
separate container, and then kept in a freezer below -20"C. HPLC grade toluene was
used to extract the samples. All extracted samples were evaporated down to lml and
then transferred into separate vials. One microlitre samples were injected into a gas
chromatograph (GC) for analysis (see Section 2.3.3 for analytical details).
2. 3. 1. 3. 2 Surface monitoring
The forehead of workers was dry wiped using 100% pure cotton pads (5 cm x 6 cm x
0.5 cm) following the period of baiting (see Plate 8).
Plate 8: Cotton Pads for Dermal Monitoring and Surface Monitoring
2.3.t.4 Dermal and ocular monitoring
Most of the data relate to the field simulation experiment (Study Group 1). Here,
samples of PPE were collected and analysed.
61
PPE samples comprised cotton inner gloves, socks and hats and full cotton overalls.
The body locations of PPE samples are shown in Figure 6.
Background levels of MAL and FEN were measured in each batch of cotton gloves,
overalls, and other sampling media. No potentially-interfering residual pesticide was
found.
After the simulation experiment, the cotton overalls were cut into approximately 20
cm x 8 cm sections (both front and back), and carefully stored in a freezer in
individual containers. Areas were pre-selected for pesticide analysis based on field
observations of work practices and judgement of sites most likely to be exposed to
spray.
Figure 6: Dermal Exposure Sampling Positions
Ocular sampling entailed the administration of one or two drops of sterile liquid to
each eye, immediately after the spraying activity. Excess liquid from the comer of
each eye was absorbed onto a sterile cotton swab. Allergan "Refresh" eye drops, from
individual sterile (single use) plastic ampoules (0.4 ml), were used. Plate 9 shows the
swab and eye drop ampoules.
62
Plate 9: Equiprnent for Ocular Monitoring
2.3.L5 Biological monitoring
Urine Sampling
Pre- and 24 hour post-spray urine samples were collected on site during the field
simulation. The samples were stored at -20"C prior to laboratory shipment.
Urine samples were sent to an extemal laboratory (WorkCover NSW) for analysis of
alkylphosphate metabolites such as dimethylphosphate (DMP),
dimethythiolphosphate (DMTP), <limethyldithiophosphate (DMDTP),
diethylphosphate (DEP), diethylthiophosphate (DETP) and diethyldithio-phosphate
(DEDTP). See Appendix 4 for an example laboratory report.
Gas chromatography with flame photometric detection (FPD) was used for the
analysis of dialkyl phosphates. Creatinine assays were performed by using the Jaffe
reaction, and colorimetric measurements were done at 500 nm.
Blood Sampling
Venous blood samples were collected into heparinized tubes by a registered nurse on
site before spraying and 24 hours after spraying. Plate 10 illustrates the sampling
equipment.
63
Plate 10: Equipment for Urine and Blood Sampling
Following centrifugation, the red cell pellet was washed twice in Earles BSS, and then
was ruptured by freezelthawing after resuspension in an equal volume of 0.2 M
phosphate buffer (pH 8.0).
Serum cholinesterase activity
This was measured by the method of Kalow and Lindsay (1955). Substrate
(benzoylcholine) was added at a final concentration of 50 mM to a mixture of 15 ¡rl
serum in 3 ml of 133 mM phosphate buffer (pH 7.\ at 30oc. The disappearance of
substrate was measured at 240 nm wavelength and was expressed as nmol substrate
hydrolyzed/ml serum.
2.3 .2 Lab oratory Methods
2.3 .2.1 Method development
Various laboratory experiments were conducted to (1) assess the pesticide desorption
efficiency from the OVS air sampling tube; (2) check on the pesticide degradation rate
during storage; and (3) optimize glove permeation testing arrangements.
64
2.3.2.1.1 OVS tube sampler
Multi-section OVS tubes (13-mm glass fibre filter, X.^D-z, 270 mgll4O *g,polyurethane foam separators) were supplied by SKC. Malathion (9s%) was
purchased from Supelco, and Fenthion (96%) from Sigma Aldrich.
The effìciency of toluene for the extraction of the pesticides (MAL, FEN) from OVS
tube components was assessed using known amounts of MAL and FEN spiked onto
polyurethane foam separators and XAD-2 porous polymer.
The desorbing solution was 3ml of toluene containing 0.5 pg of lindane/ml as an
internal standard. Lindane was purchased from Alltech.
2. 3. 2. 1. 2 Degradation experiments
According to the National Institute for Occupational Safety and Health (NIOSH,
1994b), the stability of the OPs in water is at least 30 days at OoC and 10 days at 25oC.
OVS tubes were spiked wih known amounts of MAL and FEN and degradation was
assessed over time, and in two different storage conditions, i.e. room temperatur" urrd \
-200c.
2.3.2.1.3 Test cellfor glove perþrmance qssessment
For the determination of the glove permeation resistance to pesticides (MAL, FEN),
reference was made to Australian/New Zealand Standard 2161.10.3:2002
(Occupational protective gloves Part 10.3: Protective gloves against chemicals and
micro-organisms-Determination of resistance to Permeation by chemicals.
One-inch and two-inch ASTM permeation test cells (Pesce Lab Sales, Inc. USA) were
used. For each different test cell, both compartment volume and sampling area were
measured: 18.2 ml and86.2 ml, and 4.91 cm2 and,19.63 cm2 respectively. In addition,
calibration of the test cell was conducted following ASA{ZS 2161 .10.3 (2002).
The test cell was divided into two parts. One part was for liquid or gas challenge (Part
A) and other part was the liquid or air sampling compartment for the collecting
medium (Part B). A piece of glove material was prepared and the thickness of the
specimen was measured using a micrometer. The specimen was placed between two
65
polytetrafluoroethylene (PTFE) gaskets positioned between two aluminum flanges.
The outer surface of the glove material sample was toward Part A to contact with test
chemical substances (technical grade and working strength pesticide). The two parts
were assembled by using three bolts. To Part A, the chemical or diluted solution of
interest was added. To Part B, a collecting medium was provided, such as distilled
water or isopropyl alcohol mixture with distilled water. A stirrer was put into the inlet
part of the Part B and the liquid was stirred gently. A pneumatic drive was used for
continuous stirring.
From the Part B sampling compartment, 200 ¡rl of collecting medium was taken out
and then refilled with the same amount of the collecting media. High Perforrnance
Liquid Chromatography (HPLC) was used for analysis. Figure 7 shows the standard
test cell (2") and setup of the equipment for the performance testing of PVC gloves
used by the fruit fly control workers. The small air-driven motor stirred the collecting
medium inside the test cell. In the water bath, the test cell was covered by water. The
thermo mixer circulated water coming from the pump connected to a refügeration
system. This arrangement allowed for both low and high temperature experiments.
MotorThermo Mixer
Tesr Ce[ (2
Air CompressorRefrigeration Systern
(0-20trc)
Figure 7: Standard Test Cell and Set Up of Equipment for Glove Permeating Testing
2.3.2.1.4 Preparation of the glove materials
Elbow length Protector Safety PVC gloves were used by spray applicators - Double
dipped chemical and oil resistant, 35 cm, Long, Part# IDD14, see Plate I 1.
rO
Water Bath
66
Plate 11: PVC Protector Safety Gloves Used for Fruit Fly Eradication Program
Breakthrough times (BT) and permeation rates (PR) for two parts of the gloves,
namely the palm and arm, were determined. Both used and new gloves were tested.
Before testing, two pieces (the palm and the arm) were cut out, í.e. 4.5 cm and 7 cm in
diameter for the 1" and 2" test cells respectively, and then washed and rinsed with
distilled water. After rinsing, the glove materials were dried by natural ventilation in a
fume cupboard at room temperature.
2. 3. 2. 1. 5 Collecting medium
Given the limited solubility of MAL in water, isopropyl alcohol solutions were tested
as the collection medium.
Glove performance testing was conducted at different temperatures (23oC, 30oC and
50"C) and with a range of compositions of collecting media. Each collecting medium
in the test cell, (isopropyl alcohol:water: 100:0,15:75,30:70 and 50:50) was tested
with known amounts of technical grade MAL (5 ¡rl of 43 0.7 þg/ml) and FEN (5 ¡rl of
598.0 pVml). The technical grade pesticides were transferred into 20 ml of vials
containing l0 ml of different collecting medium.
When the temperature was steady, the samples were left for five to ten minutes to
equilibrate, then 200 pl of the solution was collected for analysis by HPLC.
67
2.3.2.2 Glove testing
2. 3. 2. 2. 1 Glove materials
Samples of gloves were supplied by Protector Safety. Each was visually inspected
prior to use.
2.3.2.2.2 Breakthrough times and permeation rates
Permeation rates (pglcm2lminute) were calculated using the equation in ASA{ZS
2161.t0.3 (2002).
n (c, - cr,)(tr, -þ -t]rr,).=@Here,
P : Permeation rate, ¡rg/cm2lminute
A: area of the material specimen in contact in square centimeters ("ttt')
i : an indexing number assigned to each discrete sample, starting with i:l for
the first sample
Ti: the time at which discrete sample i was removed in minutes (minutes)
Ci: the concentration of chemical in collecting medium at time T¡ in
micrograms per litre $df)
V1 : total volume of the collection medium in litres (L)
V.: volume of discrete sample removed from the collection medium (L)
Test chemicals were technical grades, and working strengths, such as lYo technical
grade MAL (1 g in 100 ml distilled water) and 0.05% of technical grade FEN (0.05 g
in 100 ml distilled water).
To calculate the permeation rate of each glove, sample solutions were removed from
the collecting medium in Part B of the test cell and were analyzed by HPLC every 20
minutes.
68
2. 3. 2. 2. 3 Thichtess measurement
The thickness of each glove was measured at several points by using a Micrometer
(Digital 0-1 inch, 97231-67, Cole Palmer lnstruments).
2.3 .3 Analt¡tical Methods
2.3 .3 .1 Gas-chromatography
Pure toluene was used to extract samples. Analysis was in accordance with previously
published procedures (Pisaniello et a1.,2000). For MAL and FEN air samples, tubes
were extracted by the addition of 18 ml of desorbing solution, containing 0.5 ¡rg of
lindane/ml. Extracted solutions were evaporated to 1 ml, and then transferred into
separate vials prior to GC analysis.
PPE samples were extracted in 40ml of toluene. In the case of eye samples, 10 ml of
toluene was used.
For OVS tube, forehead wipe, ocular samples and glove samples (Study group 2
only), a GC with 0.33 mm id 25 m, BP5 non-polar fused silica column with electron
capture detector was used. Nitrogen was used as the carrier gas (17 psi) and as the
make-up gas (flow rate 48.5 ml/minute). Temperatures of column, detector and
injector were 175oC, 350 oC and 300 oC respectively. For all other samples, e.g. PPE
samples, a GC with TSD (nitrogen, phosphorus detector) was used.
For the GC analysis, lindane was used as an internal standard. Retention times of
lindane, MAL and FEN were 2.2 minute, 4.4 minute and 2.4 minute respectively
under the GC operating conditions used.
2.3 .3 .2 Hi gh-p erfoÍnance liquid chromato graphy (Glove p ermeation tests)
HPLC methods were adapted from those published by Kaur et al., (1997) and Abu-
Qare and Abou-Donia (2001). For this experiment, several samples of anal¡ical grade
pure MAL were tested by using three different mobile phases in order to decide on an
appropriate mobile phase. For the permeation experiments, 20 ¡rl of sample was
directly injected into the HPLC column. The HPLC conditions were 25 cm x 46 mm
69
Spherisorb ODS2 at 30oC, 1.0 ml/minute flow with helium sparging, and220 nm for
Kortec K95 UV detector.
2.3 .4 Limits of Detection
With GC-TSD, the limits of detection were 0.14 pglml for FEN and 0.29 pg/ml for
MAL, and 10 prglml was for FEN and MAL with GC-FPD. The detection limits for
overalls/PPE were 0.035 þdcm2 for FEN and 0.073 pdcm2 for MAL. In the case of
personal/air samples by using GC-ECD, the limits of detection were 0.4 pglml for
FEN and 0.Q12 pdml for MAL. For the ECD results, the limits of detection for
airborne concentration based on a sampling time of 15 minutes. The detection limit
for air sampling for FEN and MAL were I7.78 þdm3 and 0.53 þdm3 respectively.
The limits of detection forurinary samples were reported to be; DMP (1.5 ¡rmol/L),
DEP (0.7 pmol/L) and DETP, DEDTP, DMTP (0.2 ¡rmol/L).
From the HPLC analysis for glove performance, the retention times of MAL and FEN
were 14.5 minutes and around 9.4 minutes respectively. The limits of detection for
those chemicals were 0.13 pglml(MAL) and 0.005 púmI (FEN).
2.4 Results
2.4.1 Work Practices
During MAL bait spraying activities (Study Group 2), it was observed that some of
the solution leaked from the knapsack container, and the nozzle of the spray gun. The
filler screw cap seal of the knapsack was sometimes faulty, and a rag would
occasionally be used around the screw thread to control leaking. However, this was
not always effective, resulting in visible shoulder contamination. During the
application, it was observed that the workers' back, shoulders, pants, hands and shoes
were sometimes wet with the spray solution. In windy conditions, after they had
sprayed onto foliage or trees, they were covered by mist of the diluted solution on the
body and the face. After finishing the spraying or before taking a break, they took off
10
protective gloves, safety glasses or goggles and hats by hand. Their hands were
washed with water using normal detergent or soap. However, their overalls and boots
were still worn when they left to go home. Used spray equipment (knapsacks and
spray guns) were not rinsed, and were left for the next day for spraying. All used
gloves were stored in a car boot or a small container which may have been
contaminated. The inside of the used gloves were washed and dried before spraying
was started. Cotton gloves were worn under the PVC gloves by about 70o/o of the
spray applicators.
2.4.2 Survey Results
The questionnaire survey was conduced using two questionnaires, one for the exposed
group (Study Group 2) (see Appendix 2.1) and one for the unexposed group (see
Appendix 2.3). To obtain further information about gloves, another survey for the
pesticides workers was carried out (see Appendix 2.4).
2.4.2.1 Subjects
Personal baseline data are summarized for the exposed group and the unexposed
group in Table 3.
Table 3: Baseline Variables for Pesticide'Workers and Controls*
# all males* The proportions for exposed workers are not statistically different from controls (p < 0.05, two-tailed test,) (Fleiss, 1981)
Items Exposed# (n=271 Controls # 1n:et¡
Mean age (STD)(vears) 40 (110) 38 (re)
Current smokers t8 (67%) 43 (47%)
1-5 per day | (4%) 1(8%)6-10 per day 7 (26%) 7 (8%)
I 1-15 per day 3 (rr%) 7 (8%)
16-20 per day s (t9%) t2 (t3%)> 20 per day 2 (7%) t0 (tt%)
Ex-smokers s (e%) 12 (13%)
Suffer from hayfever? 7 (26%) 3s (39%)
Suffer from asthma? 3 (tt%) 7 (8%)
Suffer from eçzema? o (o%) s (6%)
More severe reaction thanothers to insect bites?
s (re%) 7 (8%)
7l
The average ages were similar. Smoking prevalence was higher among pest control
workers, but not statistically significnat. There were no significant differences for
hayfever, asthma, eczema, and insect bite sensitivity.
2.4.2.2 Symptom prevalence
Symptom prevalences are given in Table 4.
Table 4: Work-related Symptom Prevalence Data
*Statistically different proportion from controls (p < 0.05' two-tailed testr) (Fleiss' 1981)
#"Blackouts" was a dummy question included to detect positive bias in reporting symptoms
For skin symptoms, there were no significant differences between the exposed group
and the unexposed group. The exposed group attributed skin symptoms to chemical
handling and hot weather conditions. In the case of the unexposed group, the skin
problems were attributed to individual susceptibility.
However, eye symptoms (irritated, itchy and dry) and headaches were statistically
more common for the unexposed. These were largely attributed to poor air
conditioning and computer work.
2.4.2.3 Accidental exposures
Table 5 gives the results of accidents caused by chemical use. From the exposed
group, TYohad a major spill (> 500 ml). All of the exposed group used overalls during
Svmptoms Exposed (n:271 Non-exposed (n:91)
Skin symptoms
Dry cracked skin 8 (30%) r'7 (r9%\
Skin rash 3 (tr%\ s (6%\
Dermatitis/skin irritation s (re%) 4 ø%\Eye symptoms
Eye irritation* t (4%) 24 Q6%)
Itchy eyes* 2 (7%\ 26 (29%)
Dry eves* 0 (0%) ts (t7%\
Coniunctivitis 0 (0%) 2 (2%\
Others 0 (0%\ 3 (3%\
Headaches* 3 (tr%) 36 (40%)
Blackouts# 0 (0%) 0 (0%\
72
pesticide application. However, due to chemical liquid leakage from equipment or
splashes from the application, 4lo/o of the exposed group reported wet overalls during
carrying chemical solutions and spraying. Thirty seven percent had a splash in the
eyes. In most cases, eye contact occurred for people who did not wear eye protection
or who wore sunglasses and safety glasses, rather than those wearing safety goggles.
Direct skin contact by splashing with the body occurred for 37Yo of the exposed
group.
Table 5: Accidental Exposures from Chemical Use Among Pesticide Workers
2.4.2.4 Use of personal protective equipment
Table 6 provides data with respect to protective equipment usage.
Table 6: PPE Use and Work Practices Among Pesticide'Workers
Items Number (%o prevalence) n:27Maior spill l>500m1) 2 (7%\
Wet overalls from liquid leak or splash tt (4r%)
A splash in eyes ro (37%)
Splashine anv other part of the body l0 (37%\
Accident free t2 (44%\
Items Number (7o prevalencel n:27PPE usage
Overalls 27 (r00%\
Safety glasses or sunqlasses t2 (44%)
Safety goggles 3 (tt%\Protective gloves 2s o3%\Cotton gloves under qloves t7 (63%\
Foot protection
Shoes re (70%)
Boots 8 (30%)
Replacement of overalls
Once per week t6 (s9%)
Twice per week 7 (26%)
Cleanine PPE
Shoes t3 (48%)
Overalls 0 (0%)
Respirator 0 (0%)
Gloves r0 (37%\
Remove overalls at lunch break 4 0s%)
13
During the period of application, all workers wore overalls. Pesticides workers used
PVC gloves (93%) with cotton gloves (63%) underneath the PVC gloves. Sports
shoes (70%) were often worn rather than safety boots (30%). In the case of eye
protection, safety goggles (lI%) and safety glasses or sunglasses (44%) were
common.
More specific information about glove usage among pesticide workers is given in
Table 7. The maximum length of time which the gloves were used was 14 days,
because the eradication program ran for 2 weeks. However, only one of the spray bait
applicators rinsed his gloves with water before their use every moming.
Table 7: Glove Usage Among Pesticide Workers
2.4.2.5 Knowledge and training
Survey results for knowledge and training were described in Table 8
Table 8: Training and Education Among Pesticide Workers (Study Group 2)
Items Pesticides workers (n:12). %o prevalence
Baitins onlv? t2 (r00%\
Cotton undergloves used? 6 (s0%\
Full davs ofusase
3 days 4 (33%)
7 days 3 (2s%\
10 days t (8%)
14 days 4 (33%\
Has the qlove been rinsed each day? t (8%)
Items Pesticides workers (n=271, %o prevalence
Formal training in use 2s (e3%)
Period of training
1 day course 17 (63%\
> 2 davs course 8 (30%)
Education
Health effects 8 (30%)
PPE usage 20 (74%)
MSDS 20 (14%)
74
A high proportion of pesticides workers had formal training progr¿ìm (93%) in the
safe use of pesticides. Of those with formal training, 63Yo attended a l-day course,
and 30o/o attended a course of 2 or more days. In the case of training about health
effects, PPE usage and MSDS, 30Vo, 74yo and 14o/o of the spray applicators
respectively reported positively.
2.4.3 Env ironmental Measurements
2.4.3.1 Study group 1 (2001)
2.4. 3. 1. 1 Observations
The field was located on a hillside surrounded by hills. During spraying in the field,
the wind direction changed frequently. The related humidity was high due to recent
rain. The average temperature and wind speed were 14.5oC and 2.7 m/second
respectively during FEN cover spraying.
The range of wind speeds was from 0.4 m/second to 6 m/second. The wind speed
varied significantly.
Each simulation lasted approximately 15 minutes. After this time, workers were
required to remain in protective clothing until one hour after the commencement of
spraying.
2.4. 3. I. 2 Air monitoring
Table 9 gives air sampling results for the field simulation.
Table 9: Air Sampling Data (2001)
I.DAppliedchemical Total amount (pg)
Samplingtime
(minute)
Total airvolume
(m1
Airborneconc.
(urlmfPI Malathion <2 15 0.023 <92P2 Malathion <2 15 0.023 <92P3 Malathion <2 l5 0.023 <92P4 Fenthion T3 15 0.023 565
P5 Fenthion 18 18 0.027 666
P6 Fenthion 8 l3 0.020 400
MAL Limit of detection 2 pg
7s
For bait spraying, no MAL was detected for any of the air samples collected.
However, FEN was detected for the workers spraying FEN. The airbome
concentration of FEN ranged from 400 to 667 ¡t"gl m3. Cover spraying generated
significant aerosol which was swirling due to weather conditions.
2.4.3.1.3 Overalls
Table 10 gives the detected quantity on the overall samples from MAL bait spraying.
In general, workers held a spray gun with their left hands and operated the piston with
the right. Only two samples had detectable MAL. These were on the left forearm,
where, based on observation, spray was most likely to deposit.
Table 10: Malathion SprayWorkers' Overalls Samples (2001)
Limit of detection 0.07 pglcm2
LFF; lcft forearm front, RFF; right forearm front, LSF; left shoulder front, RSF; right shoulder front,
Table 11 gives the corresponding data for FEN cover spraying. It was observed that
workers normally had their left side of their body facing toward the sprayingarca.
Table 11: Fenthion Spray Workers' Overalls Samples (2001)
LCX'; left chest front, RCF; right chest front, LLAF; left lower arm front, RLAF; right lower arm front
Limit of detectíon: <0.04 pglcm2
I.D. Appliedchemical
ConcentrationLF'F' RT'F' LSF RSF'
P1 Malathion 0.32 <0.07 <0.07 <0.07
P2 Malathion 0.11 <0.07 <0.07 <0.07
P3 Malathion <0.07 <0.07 <0.07 <0.07
I.D. Appliedchemical
ConcentrationLCF' RCF' LLAF' RLAF'
P4 Fenthion 0.2t 0.14 0.09 <0.04
P5 Fenthion <0.04 0.06 <0.04 <0.04P6 Fenthion 0. l0 0.11 0.12 0.2
76
2.4.3.L4 Other PPE monitoring
The workers' inner cotton gloves, socks and hats were collected and analyzed. Table
12 gives results. Most samples had no detectable pesticide.
For MAL bait spraying, the range of pesticide measured was from 0.09 to 0.69
mglcm2. The highest concentration was measured for a hat containing 0.69 mflcmz
from Pl. However, FEN cover spray samples generally did not have detectable
pesticide. Only the left glove of P6 had some pesticide (0.03 mg/c*'¡. Ar the cotton
gloves were woÍì under the PVC protective gloves, it is likely that contamination
occurred when removing gloves.
Table 12: Workers PPE Samples (undergloves, socks and hats, 2001)
LG; Left cotton glove, RG; Right cotton glove, LS;Left cotton sock, RS;Right cotton sock
ND; Not detected. Limit of detectioil: FEN 1O.Ot mg/cm2¡, MAL(0.01 mg/cm2)
2.4. 3. 1. 5 Ocular monitoring
No detectable pesticide was found.
2.4. 3. 1. 6 Biological monitoring
Dialkyl phosphates were not detectable in any worker urine samples. Similarly,
cholinesterase activities were not depressed (see Table 13). Collectively, these
demonstrate low uptake of pesticide during the field simulation experiment.
I.D. Appliedchemical
ConcentrationLG RG LS RS Hat
P1 Malathion 0.39 0.51 0.26 0.09 0.69P2 Malathion ND ND NDP3 Malathion 0.31 0.09 ND ND NDP4 Fenthion ND ND ND NDP5 Fenthion ND ND ND ND NDP6 Fenthion 0.03 ND ND ND
l7
SChE (pmol/minute/ml serum)
Subìect Pre-simulation Post-simulationM1 t2.3 11.3
M2 14.6 14.8
M3 13.5 t2.1F1 14.4 16.1
F2 ts.7 16.8
F3 10.8 13.0
Table 13: Serum Cholinesterase levels pre- and post exposure (2001)
2.4.3.2 Study group 2 (2003)
2.4. 3. 2. 1 Observations
The field sampling involved collection of forehead wipe samples and inner cotton
gloves for 8 workers. During the baiting, the average temperature was about 30oC and
it was sunny weather and dry conditions. There was little or no wind on the sampling
day.
2.4.3.2.2 Forehead wipe and PPE monitoring
All the samples including forehead samples were collected as soon as the sprayers
finished their work. The samples were transferred to clean bottles and stored in the
freezer prior to analysis.
Table 14 gives the results.
Table 14: Malathion in Skin Wipe and Inner Cotton Glove Samples (2003)
FH; Forehead, RG; Right cotton glove, LG; Left cotton glovc.
I.D.Concentration (¡rqlcm2)
F'H RG LG
S1 0.2r L34 0.57
S2 0.25 2.97 24.7
S3 0.05 0.23 0.27
S4 0.03 1.60 3.19
S5 0.09 1.51 1.81
S6 0.02 10.8 5.16
S7 0.03 0.92 2.30
S8 0. l0 2.77 2.73
78
All workers used the right hand or both hands during the baiting onto trees and
foliage. Baiting time was nominally around 2 hours for each worker.
2.4.4 Laboratory Analysis
2.4.4.1 Optimized analytical conditions
2.4.4.1.1 Desoprtion efficiency of XAD-2
The OVS tube (see Plate 7) used in this study comprises a glass fibre filter, two
polyurethane foam separators and two layers of XAD-2 porous polymer.
Table 15 gives the pesticide recovery rates from XAD-2 and polyurethane foam in the
OVS tube with different concentrations of technical grade MAL and FEN. Toluene is
the desorbing solvent.
Table 15: Desorption Eff,rciency of Malathion and Fenthion from OVS TubeComponents Using Toluene
Known amounts of technical grade MAL (58% purity) and FEN (55%) were spiked
on tubes. Recovery rates from polyurethane foam andXAD-2 were 89Yo and72o/o for
MAL and 860/o and 70o/o for FEN. According to NIOSH (1994b), the acceptable
desorption criteria for OPs is > 75o/o average recovery with a standard deviation of
less than 9%.
Sample Percent recoverv (7o) AM (%) STD
0.015re/rnl MAL(M-stdl)0.025pelrù MAL(M-std2)0.039ue/ml MAL(M-std3)Foam with M-std1 80
89 9Foam with M-std2 97
Foam with M-std3 90
XAD withM-stdl 6t72 t6XAD withM-std2 64
XAD withM-std3 91
0.006pe/rnl FEN(F-std1 )0.032pe/ml FEN(F-std2)
Foam with F-stdl 9686 t4
Foam withF-std2 76
XAD withF-stdl 7670 8
XAD withF-std2 64
19
It was established that the retention of pesticides on the glass fibre filter of the OVS
tube was negligible.
2.4.4.1.2 Storage and analytical limitations
Prior to field work, experiments were done to determine the OVS tube sample
stability with storage method, í.e. fteezer or room temperature.
The two kinds of samples were labeled as "R" (stored at room temperature) and "F"
(stored in a freezer). Table 16 gives the comparison of the two conditions and the
recovery percentage with time in storage. The samples stored in the freezer appeared
to display more stability within ten days. From these data, it was decided that all
samples should be stored in afreezer.
Table 16: Recovery of Malathion and Fenthion from OVS Tubes by Time andStorage Method
Malathion; 4.2 ¡tglml, Fenthion; 2,24 pglml,
R; Stored at room tpmperature (25"C), F; Stored in freezer (approx -20oC)
2.4.4.1.3 HPLC mobile phase
HPLC was used for the analysis of MAL and FEN during glove permeation
experiments.
Time (Hours) Percentage recovery (7o)Malathion-R X'enthion-R
0 0 026 100 10099 92 88
195 89 89240 87 89
AM.lSD 92!6 92+6
Time (Hours) Percentage recovery (o/o)
Malathion-F tr'enthion-tr'0 0 0
26 103 10976 99 98195 92 90240 95 95
AM.tSTD 97 !4 98r8
80
Different mobile phases were tested to optimise sensitivity and linearity of response.
Table 17 gives the results for MAL.
Table 17: Comparison of Different Mobile Phases to Detect Malathion by HPLC
Data indicated that the second mobile phase (50% acetonitrile:water, pH 6.0) gave the
greatest sensitivity.
Table 18 shows the sensitivity of the UV detector for the same mobile phase, in the
case of FEN. The extrapolated limit of detection was 0.005 pdml.
Table 18: Sensitivity of HPLC UV Detector for Fenthion
* Linear regression
2.4.4. 1.4 Collecting medium
Distilled water and isopropyl alcohol (0, 15, 30 and 50%) were tested as liquid
collecting media in the permeation test cell. The reason for selecting isopropyl alcohol
as a co-solvent was that it was likely to improve solubility of malathion and there
Malathion conc. (pglml)Area of UV signat (x 10-3)
637n acetonitrilepH 6.0
507o acetonitrilepH 6.0
50%o acetonitrilenH 4.0
0.46 n.d. 3.05 n.d.
4.s7 12.5 29.4 22.2
9.t4 43 82.6 93.8
45.7 385 408 222
4s7.0 29t4 3271 I 865
4570.0 t8931 293',76 22259
Rf ûinear reqression) 0.997 0.9999 0.9997
Approx. Limit of detection (pglml) L49 0.1 25 1.28
f,'enthion conc. (pglml)Area of UV sisnal (x 10-3)
507o acetonitrilepH 6.0
0.07 195
0.23 224
2.25 2013
2.31 20t32.91 3s'|3
R' 0.994
Approx. Limit of detection (uelml) 0.00s
81
were no reactions with the tested glove materials (PVC and Nitrile gloves) and no
interference on the HPLC.
In initial experiments with the permeation test cell, using technical grade MAL as the
challenge material, it was found that there was a difference between pure water and
50% isopropyl alcohol, i.e. lower MAL concentrations for water under the same
experimental conditions.
In order to establish a IPA:water mixture that could serve as a suitable collection
medium, the following experiment was conducted:
Known amounts (5 frl) of technical grade MAL and FEN were added to different
IPA/water mixtures (10 ml). The solutions were shaken and allowed to stand for
several minutes.
Samples were injected into the HPLC. The experiment was repeated at 30oC and
50oC. Table 19 gives the MAL concentrations measured and shows lhat30Yo and l5Yo
of isopropyl alcohol in distilled water provided best solubility for MAL and FEN
respectively.
Table 19: Solubilities of Malathion and Fenthion in Different Collecting Media
Temp (oC) Detected concentration of fenthion luelÍtl)0o/oIPA 15% IPA 30% IPA 50% IPA
23 8t% 98% 89% 89%30 82% 95% 93% 97%50 7s% 88% 89% 95%
IPA: isopropyl alcohol
However, when solutions were kept at 50oC for several hours, there was significant
decomposition of both MAL and FEN. This precluded glove experiments at 50oC for
extended periods.
Temp (oC) Detected concentration of malathion (uelml)
O% IPA 15% IPA 30% IPA 50% IPA23 32% 64 Y" 97% 94%30 3'.t% 84% 97% 90%50 23 Yr 87% 96% 8r%
82
2.4.4.2 Glove testing
2.4.4.2.1 Effect of temperature (30o/o Isopropyl Alcohol)
The elbow length Protector Safety PVC gloves were tested for permeation resistance
against working strength MAL and FEN at different temperatures and using different
collecting media. Table 20 gives the observed BTs and PRs of the glove material.
At the ambient temperature, neither MAL and FEN were detected from the palm and
lower arm within 24 hours. However, MAL was detected at3loC. When the palm and
the lower arrn were compared, the palm had a longer BT and lower PR.
Table 20: Breakthrough Times and Permeation Rates of PVC Glove Material underVarious Conditions
Each sample wâs run three times
1) 0.05% of Technical Grade Fenthion: 0.059 in 100mI distilled water,2) l7o of Technical Grade Malathion: lg in 100m1 distilled water,3) Temperature,4) Breaktlrrough time,5) Permeation rate, TG; Technical Grade, IA; Isopropyl alcohol, PVC Pro. Safety; PVC
Protector Safetyfr, llD; Not detected within 24 hours,
The breakthrough times and permeation rates for gloves exposed to fuIl technical
strength versus working strength at different temperature are given Table 2l.Thirty
percent isopropyl alcohol in distilled water was used for MAL. In addition, pure
Testchemical
Workingstrength
Collectingmedia
Glove materiallocation
Temp(oC)3)B.T
(minute)a)P.R.s)
(pgicm2lminute)
Fenthion0.05%r)
water
Palm22+l > 1440 N.D37+l > t440 N.D
Lower Arm22!l > 1440 N.D37+l > 1440 N.D
I5% IPA Palm22tl > 1440 N.D37+l > 1440 N.D
Lower Arm22+l > 1440 N.D37+l > 1440 N.D
Malathionl%oz)
water
Palm22+l > 1440 N.D
37+l1428,1434,
t43t 1.2,1.2, 1.2
LowerArm22+l > 1440 N.D
37+I1381,1386,
13841.3, 1.3,1.3
30% IPAPalm
22+l > 1440 N.D
37+l1151,1156,
1 1545.3,5.2,5.3
Lower Arm22!l > t440 N.D
37+l 564,568,567 7.7,7.7,7,6
83
distilled water was used as a comparison with 30% isopropyl alcohol. Two parts of
the glove were selected to test. They were the palm and the arm. Samples were run in
triplicate.
Table 2I: Breakthrough Times and Permeation Rates of New PVC Gloves withTechnical Grade and Working Strength Malathion
(1) Part: Palm
(2) Part: Arm
Each sample was run tltree times
ND; Not detected within 24 hours
1) Collecting media in the collecting cell,2) Chemical to pass through the glove material,3) Breakthrough time of malathion,4) Permeation rate,5) 30% of Isopropyl Alcohol in distilled water,ó) Pure Technical Grade malathion used in the lÌeld (58%o malathion),
7) 17o of technical grade (T.G.) malathion in 100mI of pure water as working strength in the field (0.58olo malathion),
Part of the palms of the gloves were coated with extra rubber, i.e. the palms are
thicker. With technical grade MAL, the breakthrough time for the palm was slightly
longer in distilled water compared with 30% isopropyl alcohol at room temperature.
At37oC, the breakthrough times in distilled water and the 30% isopropyl alcohol were
Tempfc) Coll. media r)
Thickness(mm) +0.02
Challenge.chemical 2)
B.T 3)
(minute)P.RO'
luslcm2/minute)
22+l DW 1.32 Tech. Grade o) 1335, t340,1337 0.01, 0.01, 0.01
30% IPA,, 1.33 Tech. Grade 1012, 1005, 1009 0.02, 0.03, 0.03
37+l DW 1.30 Tech. Grade 1062,1066,1064 r.9 , t.6, r.730% IPA t.32 Tech. Grade 860.864.862 47 .3.46.0. 46.6
22+l DW 1.34 lo/n of T.G ') > 1440 N.D3OYOIPA t.32 1% of T.G > 1440 N.D
31+IDW t.29 lY" of T.G 1428, t434, t43t 1.2,1.2,1.2
30% IPA 1.28 l% of T.G 1151, l156,tl54 5.3. 5.2,5.3
Tempcc)
Coll. media 1)Thickness
(mm)r0.03
Challengechemical 2)
B.T 3)
(minute)P.R4)
(pglcm2/minute)
22+l DW 1.10 Tech. Grade o/ 1306,1310,1308 0.01, 0.01. 0.0130% IPA,J 0.96 Tech. Grade 80s.812,809 0.03. 0.03. 0.03
37+lDW 1.15 Tech. Grade 928,917,923 1.6,2.4, LI
3O% IPA 1.13 Tech. Grade 508. 502. 505 50.0. 58.8. 53.0
22+l DV/ 0.99 lo/, of T.G ') > t440 N.D.3OYOIPA,, 0.99 1% of T.G > 1440 N.D.
37+IDV/ l 06 lYo of T.G 1381,1386,1384 1.3, 1.3, 1.3
30%TPA t.02 1% of T.G 564.568.567 7.1,1.7,',l.6
84
1064+3 minutes and 862+3 minutes respectively. With working strength solution,
there was no detectable breakthrough in distilled water and for 30% isopropyl alcohol
at ambient temperature. The test was prolonged for up to 24 hours. However, at
3J+1oC, the breakthrough time was detected at around 143I minutes in distilled water
and Il54 minutes in the 30% isopropyl alcohol.
The arm section of the gloves had shorter breakthrough times (1308 t3 minutes in
distilled water, 809 +5 minutes 30% IPA) and higher permeation rates (0.02t0.01
p,glcmzlmirntte in distilled water, 0.03+0.01 pglcm2lminute in 30% IPA) compared
with the palm. There was no MAL solution breakthrough up to 24 hours with the
working strength solution. At 37+1"C, the permeation rate in30Yo IPA was about 25
times higher than in water with the technical grade MAL. When the temperature was
changed from 22+loc to 37+1oC, the breakthrough times were decreased by 14.5%
(palm) and 31.5o/o (am). Under the same conditions, permeation rates were increased
by greater thanI00%o (palm, arm).
2.4.4.2.2 Perþrmance of used PVC gloves
For Study Group 2, new gloves were provided to each worker before commencement
of MAL bait spraying on the first day. Two pairs of gloves were then randomly
removed from workers at defined periods and tested for permeation resistance in the
laboratory.
The palm and the arrn were cut out from left and right gloves for testing after the
gloves had been used for 3,7 and 14 days. The used gloves were tested with technical
grade MAL in order to determine breakthrough time and permeation rates. This would
provide the worst case scenario rather than using working strength MAL solution.
Samples were run in triplicate, and two used gloves were tested for each situation.
The results are reporte d in T able 22.
Pqlm
With the gloves used for three days, breakthrough times of the palm were between
240 minutes and 617 minutes, and permeation rates were between 0.04 ¡tglcm2lminute
and 0.05 p{cmzlminute. Gloves used for seven days had shorter breakthrough time
85
(101 minutes to 189 minutes) and higher permeation rates (0.04 ¡rglcm2lminute to 0.3
¡rglcm2lminute).
In the case of the gloves used for 14 days, thebreakthrough time was decreased to a
minimum of 33 minutes and the permeation rate was up to 0.8 ¡rglcm2lminute. There
is some evidence that the palm of the left hand gloves has lower breakthrough times
than right hand gloves. The reason for this might be that most of sprayers used their
left hand to gnp the spray gun and pushed the piston up and down with right hand. In
the case of the right palm of the glove used for 7 days, breakthrough times could not
be detected. The glove material was already contaminated with high concentrations
and MAL that had passed through the glove material before the analysis.
Arm
As the worst case, breakthrough times for the arm dropped down from 562 minutes
with gloves used for 3 days to 81 minutes with gloves used for 14 days. The
permeation rates were increased from 0.06 pglcm2lminute (3 days used glove) to 0.4
p/cm2lminute (14 days used glove).
Table 22: Breaktl'rough Time and Permeation Rate of Used PVC Gloves withTechnical Grade Malathion at22oC
(1) Part: Palm
Period of Use(days) 1) Location Thickness (mm)
(AM+STD)8.T,,
(minute)P.R,)
(uslcm2lminute)
J
Left 1.31+0.05 400 0.041.31+0.05 240 0.05
Right1.30+0.01 6t7 0.041.27+0.03 402 0.04
7
Left 1.28+0.01 189 0.041.2'7+0.02 l0l 0.30
Right1.28+0.01 N.A.* 0.191.26+0.03 140 0.35
t4Left 1.25+0.01 33 0.40
1.24+0.03 73 0.50
Right1.l8+0.04 86 0.237.20t0.02 49 0.77
86
Period of Use(davs) 1) Location
Thickness (mm)(AM+STD)
B.T 2)
(minute)P.R,)
luslcm2/minute)
J
Left0.98+0.02 565 0.06
0.97+0.03 562 0.06
Right0.99+0.07 512 0.06
0.94+0.04 572 0.06
7
Left 097+0.02 484 0.05
0.95+0.01 191 0.06
Right0.95+0.01 541 0. l90.94+0.03 308 0.03
t4Left
0.93a0.01 t't I 0. l30.90+0.033 153 0.12
Right0.88+0.012 87 0.07
0.9210.0'71 81 0.45
(2) Part: Arm
* Breakthrough occurred immediately. The initial amount in the fìrst minute was estimated to be 1.3 p{cm2.
1) Period of the usage of glove (3.Shours per day),2) Breaktlrrough time of malathlon,3) Permeation rate,
2.4.4.2.3. Thickness changes observed during use
Unless gloves were removed, sprayers used the same gloves everyday without
replacement over the two week period. In the case of workers whose gloves were
removed, a new pair was provided (without further testing).
The thickness of the gloves was measured and reported in Tables 2I and 22. The palm
and the arm thicknesses should be compared with new gloves (Table 21). Thicknesses
generally decreased with usage time, with coffesponding reductions in breakthrough
time.
2.5 Discussion
This appears to be the first systematic study of occupational exposure to MAL and
FEN during Mediterranean fruit fly eradication activities.
In 2001 a group of 6 pesticide applicators applying MAL and FEN in a field
simulation were intensively studied.
In 2003 a group of 27 }r'4AL bait sprayers v/ere investigated using questionnaires and
limited dermal exposure assessments were conducted with 8 workers.
87
In addition, the resistance of PVC gloves towards permeation by MAL and FEN were
tested under conditions of variable concentration, temperature and worker use.
'With respect to the research questions given in Chapter 1, the following conclusions
may be drawn:
o Evaluation of dermal exposures, in total and in respect to particular areas of
exposed skin, e.g. hands, and assessment of the opportunities of exposure;
For MAL bait sprayers involved with the field simulation, it appears that the heaviest
exposure is on the left front forearm (Table t0). For FEN sprayers, the contamination
is more widespread which is consistent with cover spray activities. Glove
contamination was detectable in many cases, with some values being high. One
worker (Pl, Table 12) was observed to transfer contamination from outer gloves to
inner gloves and socks upon removal. Indeed, surface contamination transfer by poor
work practice and storage may represent a significant means of exposure in these
pesticide applications. Skin wipes of the forehead in 2003 yielded relatively low
values indicating that aerosol deposition is minor. This is consistent with air sampling
data (Table 9). In the case of cover spraying with FEN, the air concentrations would
be in excess of the TWA Exposure Standard of 0.2 mdm3 if the spraying were done
throughout the day. The observations made during the course of both studies indicate
that visible liquid contamination of clothing can occur from leaking equipment, poor
work practice or skill, or unfavourable wind direction. Opportunities for exposure
include
(1) leaking knapsacks or splashes resulting in direct contact;
(2) contamination transfer due to poor storage and removal of PPE; and
(3) aerosol deposition, especially for FEN.
88
o Evaluation of chemical contamination of the eye surface, arising from the spray
application of chemicals;
Pesticide was not detected in the eye during the field simulation, possibly as a result
of effective eye protection, but perhaps also due to dilution/decomposition of
pesticide on the eye surface prior to ocular sampling. All other factors being equal it is
likely that cover spray will result in more ocular exposure than bait spray.
o Prevalence of skin and eye-related symptoms, in absolute terms and in comparison
with a control group of unexposed workers;
Skin symptoms were relatively common among the exposed workers, and more
prevalent than for controls. However, the difference was not statistically significant.
In a study of nurses by Pisaniello et al., (1994), dry cracked skin and rashes affected
39o/o and 13olo respectively. In general terms, skin problems among pest controllers
could be considered moderate.
Eye symptoms were, in fact, more common among the controls. The low prevalence
of eye irritation is not readily explained, although eye protection was routinely worn
by the operators, who mainly worked outdoors,
Comparison of measured exposures with observed work practice, equipment and
control measures;
a
As previously mentioned, observations of leaking equipment, personal hygiene and
poor storage of PPE can be correlated with dermal exposures of the hand and forearm.
These results are consistent with other studies. In a study by Pisaniello and coworkers
(2000), contamination of foreheads by hand contact was observed. Similarly, smoking
of externally contaminated cigarettes facilitated the contamination of the mouth area
and inhalational exposure. In the present study, no measurements of vehicle cabin
contamination were carried out. However, it is known that eating in contaminated
vehicles and touching contaminated steering wheels or gear sticks may contribute to
exposure (Cattani et al. , 2001). From Table 6, it can be seen that only I 5olo of workers
removed potentially-contaminated overalls during their lunch break.
89
. Evaluation, where feasible, of uptake using biological monitoring methods and
correlation with ambient and dermal measurements;
Serum (plasma) cholinesterase depression and the presence of dialkylphosphates in
urine were used for biological monitoring in this study. Whilst there was evidence of
skin contact with MAL and FEN, biological monitoring results demonstrate low
uptake. Coupled with questionnaire data, these suggest low health risk. There is a
paucity of information on the rate of transdermal penetration by MAL and FAN,
especially for working strength solutions. Existing data (ATSDR, 2000) suggest
inefficient penetration through the intact skin.
The field simulation experiments in 2001 were of limited duration, entailing only
about 75 - 100 minutes of contact with potentially contaminated clothing. No BM was
conducted during the 2003 fruit fly outbreak. Thus it is possible that partially
contaminated and/or absorbant PPE (Garrod et al., 1998) may represent only a small
health risk if it is worn for short periods. On the other hand, damaged, hot or occluded
skin will increase the likelihood of uptake. Further work is required to clarifli the issue
under actual field conditions, and preferably in hot weather.
. Assessment of PPE service life, in particular repeated usage of gloves, in actual
field use and in simulated laboratory experiments.
This study has shown that the elbow length PVC gloves currently used by PIRSA
staff are effective under normal conditions. However, over a period of two weeks of
daily usage, a measurable decrease in thickness and permeation resistance occurred,
without any obvious change in physical appearance. Furthermore, differential wear is
possible, depending, for example, on the technique and handedness of the operator.
Breakthrough times after two weeks usage were approximately one hour for technical
grade MAL at room temperature (Table 2l). At elevated temperature, resistance
would be further decreased (Table 20).
It appears that a marked reduction in performance occurs after one week, and thus it
would be desirable to replace gloves after one week of usage.
90
Limitations
This study is limited by the fact that there was only one small fruit fly outbreak in
2003, and the fieldwork only lasted two weeks. Fenthion cover spray was not
evaluated under actual field conditions due to a temporaryban from 2001.
Hence, the sample size of applicators was relatively small for questionnaire purposes.
Due to practicallcost limitations, it was not feasible to analyse all available PPE. In
the case of cotton overalls, sections were pre-selected for analysis based on visible or
observed contamination.
Strengths
This is one of the few studies that has examined service life of gloves (Klingner and
Boeniger, 2002). By a combination of thickness and permeation measurements in two
sections of gloves it was possible to assess the impact on peformance, arising from
repeated use under actual field conditions.
The ability to observe the effect of temperature was also a strength.
Although no residual pesticide was found in the eyes of applicators, this appears to be
the first study to specifically look for it.
Careful observation of work practice, coupled with environmental and biological
sampling and questionnaires has enabled an assessment of health risk due to the use of
MAL and FEN for fruit fly control.
Recommendations
The following recommendations can be made to further reduce exposures;
Leaking equipment should be replaced or repaired.
Suitable facilities should be provided in the vehicle for storage of PPE. Gloves,
respirators and overalls should be separated to avoid cross contamination.
Applicators should be given training on proper removal and storage of PPE so as
to avoid secondary contamination.
a
a
a
9l
o Hands should be washed prior to eating and smoking, and this should not be in the
vehicle cabin.
Proper chemical resistant footwear should be provided.
Elbow length PVC gloves should be replaced after approximately a week of use.
2.6 Conclusions
From the simulation study in 2001, questionnaire data in 2003, and discussions with
workers and supervisors, it appears that exposure to MAL and FEN under the
circumstances of use is insufficient to cause appreciable health problems. However,
pesticides were commonly detected in glove samples, on the forehead, and on the
forearm, and chest regions. Visible contamination was occasionally observed on the
back, forearms and lower leg regions due to leaking equipment. There was also the
potential for an accumulation of pesticides on inappropriate footwear and subsequent
exposure.
Glove permeation tests, under conditions of variable use, temperature and active
ingredient concentration, were conducted. In the case of gloves used for malathion
bait spraying, the polyvinyl chloride gloves provided good permeation resistance
when new. However, significant reductions in performance were observed after two
weeks of usage. In addition, the physical appearance of the gloves did not give any
indication of their lowered breakthrough time.
Ocular exposure was not detectable in the circumstances.
a
a
92
CHAPTER 3. DERMAL AND OCULAR EXPOSURE TO
HEXAMETHYLENE DIISOCYANATE (HDI)
BASED PRODUCTS
3.L Introduction
An introduction to isocyanates used for spray painting has been given in Section 1.7
of Chapter 1.
The two industries selected for isocyanate exposure assessment were automotive
spray painting and fumiture manufacturing.
The spray painters from the two industries agreed voluntarily to undergo skin and
ocular monitoring after finishing spray painting. However, no biological monitoring
was conducted, because of the difficulty of the detection of suitable metabolites. In
addition, urinary hexamethlenediamine (HDA) is not likely to be a useful biomarker
to monitor HDI exposure.
In order to investigate exposure levels and the prevalence of adverse health symptom
prevalence, questionnaire surveys and a range of sampling methods were applied (see
Section 3.3). Glove permeaion testing was conducted to determine glove performance.
All results are described in Section3.4.
3.2 Study Populations
In 2003, a number of private automobile repair workshops and two apprentice training
schools in SA were investigated. A mobile touch up spray painting situation was also
investigated. Spray painters usually applied isocyanate-based (two-pack) paints inside
a dedicated spray booth (Plate 12) or enclosure, collectively termed "indoor"
spraying. In some cases, spraying was carried out undercover but subject to natural
ventilation (termed "outdoor" spraying), e.g. carport.
Either panels or a whole body of a car were sprayed inside the spray booth.
93
Plate 12: Two-Pack Spray Painting in Crash Repair Shops
In2004, spraying in a private furniture manufacturing company was also investigated.
Spray painting was conducted inside the spray booth (Plate 13).
Plate 13: Two-Pack Spray Painting in The Furniture Industry
3.2.1 Study Group 3 (Crash Repair Shops & Associated Industries, 2003) *
Twenty six spray painters participated in this study. Of these, 21 workers were
qualified spray painters in crash repair workshops, and the others were apprentices
from a TAFE college (1 worker) and a Motor Trade Association (MTA) training
. Study group 1 and 2 were described and exposures discussed regarding to thepesticides study (Chapter 2)
94
school (3 workers), and one mobile spray painter. A list of crash repair workshops
was provide by the MTA and an introductory letter was sent in advance (see
Appendix 5). Nine workshops (50%) agreed to participate. The non-responders did
not appear to be different from the responders in terms of workshop size or location.
For vehicle refinishing, a sealer/filler containing isocyanate was often used in order to
seal small gaps or holes on the auto body surface. The surface was left for around 12-
17 hours, and then rubbed down by using very fine sand paper or a powered sander.
The surface was rinsed and dried, and masked up. Before the spray painting, the spray
booth was typically heated up to 30oC for 10-15 minutes. The paint ingredients were
then mixed, i.e. HDl-based hardener, resin base (clear or colour) and reducer, and
poured into the spray gun.
A range of hardeners used in the automobile repair industry, such as PPG (2K MS
Normal Hardener 980-35239), Spies Hecker (2K-Acryl-System, Permacron, MS Plus
Hardener, Slow 3030,975-65507) and Sikkens (Autocryl, HardenerMS l0) (Mohanu,
ree6).
Either a conventional (high-pressure) or an HVLP (high-volume low-pressure) spray
gun was used with between 20 and 70 psi air pressure. After all these procedures,
baking was conducted at around 60oC for 45 minutes. The application time was about
20 minutes for a small part of a car. When this process was completed, the small part
or car was left for 2-3 hours to completely harden.
Workers usually wore overalls, gloves respiratory protection, and in some cases eye
protection.
3.2.2 Study Group 4 (Furniture Industry, 2004)
A large furniture manufacturer in SA agreed to assist with this study. This group
included spray painters using isocyanate-based spray paints. Three spray painters and
one spray paint mixer were involved in this study.
In this furniture manufacturing company, very low concentrations of isocyanate (0.1
mgNCO/g liquid hardener) were used for 2-pack spray painting. HDl-based hardener
(AKZO NOBEL; Fast, No 895002013, Code 310.700) was used.
9s
There was a preliminary spaler for wood panels or small pieces of wood before the
application of the 2-pack spray paint in a spray booth. After applying the sealer, the
wood panels or small pieces of wood were moved to either of two spray paint booths,
an automatic spray booth and a manual spray booth. For the spray painting, the main
components of the spray paint were resin:hardener (2:1) and reducer (approx. I0o/o in
total).
The spray paint mixer prepared spray paint for the automatic spray painting system
and provided spray paint for the spray painters working in the manual spray booth
which had a water curtain system and a small duct system at the ceiling. In general,
small articles were sprayed. The application time was about 20 minutes for 2 or 3
pieces. The mixing area was not enclosed.
The two different spray booths shared the same collecting room. After finishing the 2-
pack spray painting from both spray booths, all the sprayed wood panels and small
articles of wood were stored in the collecting room (average temperature was around
26oC) to dry out for 12-15 hours. Workers wore overalls, respirators and eye
protection.
3.3 Methods
3.3. I Fieldwork Methods
For the isocyanate spray paint applicators, araîge of methods were used:
Health and work practice questionnaire, personal air samples, general area aír samples
away from spraying spots or spray booths, ocular sampling, skin wipes, skin patches
and PPE samples (respirators and goggles).
3.3.1. 1 Questionnaire survey
3. 3. 1 . 1 . 1 Development and pilot investigation
A cross-sectional study was conducted for the isocyanate (HDI) spray painters similar
to that for pesticide workers.
The aim of project was explained to the workers by a member of the research team
and an information sheet was supplied to the exposed group (see Appendix 1.2), and
96
they were interviewed individually. They were given an opportunity to ask questions
and then asked if they wished to participate. If they agreed, a consent form was issued
(see Appendix 1.3), along with a complaint form (see Appendix 1.4).
The questioruraire based on a previous questionnaire (Pisaniello et al., 2000) for
workers implementing isocyanate (HDD spray painting. The strategy of this
questionnaire was the same as for the pesticide workers.
This questionnaire included personal information (name, date of birth, sex, worþlace,
job title, work experience and educational status), health information (respiratory
symptoms, skin symptoms, ocular symptoms, other symptoms and smoking status)
anrl work practices (chemical usage and PPE usage) (see Appendix2.2).
The control group was the same as for the pesticide workers in Chapter 2.
3.3.1.1.2 Administration and human ethics
Ethics approval was given by the Human Research Ethics Committee of The
University of Adelaide. Notification of approval was provided in a letter dated in
March, 2003 (see Appendix 3.2).
The author selected volunteer operators who were exclusively using isocyanate (HDI)
during the 2-pack spraying painting.
3 .3. 1 . 1 .3 Data analysis
The same data storage system was used for personal confidential information as for
the data from the pesticides workers as well as statistical analysis (see Section
2.3.r.t.3).
3.3.1.2 Worksite observations
In order to observe working environment and conditions, semi-quantitative Dermal
Exposure Assessment (DREAM) based on dermal exposure assessment (Van-
'Wendel-De-Joode et al., 2003) was adopted. A worksite observational sheet was
97
developed, and -used for the inspection of the areas in which isocyanates-based
products were used and for examining dermal exposure (see Appendix 6). This sheet
includes worþlace name (company), workshop size, procedures, environment,
ventilation system, chemical used, contamination areas on the body, exposure status,
cleaning status and PPE use.
3.3. 1.3 Environmental measurements
3.3. I. 3. 1 Air monitoring
Air monitoring was conducted in order to provide quantitative inhalational exposure
data in the worþlace. Impregnated glass fibre f,rlters were used following the HSE
MDHS 2513 method (HSE, 1999). For personal ak monitoring, an air sampler
(cassette type-composed of three parts) was attached within the worker's breathing
zone at a flow rate of 1 Liminute controlled using an air sampling pump (Plate 14).
The flow rate was checked using a calibrated rotameter prior to and after sampling. In
addition (for group 3 only) positional air samples were collected at various distances
to determine potential exposure of other employees and how far isocyanate spreads.
Plate 14: Air Monitoring Apparatus for Isocyanate (HDÐ
3. 3. I. 3. 2 Surføce monitoring
For surface monitoring, color change was observed from contaminated surfaces using
a Paper Tape (Replacement Detection Tape Cassette; Aliphatic Isocyanates, GMD
SYSTEMS Inc.) and commercial products (Permea-TecrM Colorimetric Swype
98
Indicators, Package of 25 Surface SWYPESTM (Aliphatic. Iso.; J-ISOAL-SUR),
Package of 25 Skin SWYPESTM (Aliph. ISO.; J-ISOAL-SKN) and Package of 20
pads (Aliphatic Iso.; J-ISOAL-PERM, Omega Speciality Instrument Company,
USA)). Plate 15 shows the Paper Tape and the Permea-TecrM Pads. The Colorimetric
Swype Indicators were recommended by Lawrence (2002).
The selected contaminated areas and PPE were wiped. Before wiping surfaces and
observing color changes, pure IPA was sprayed on the surface (see Section3.4.4.l.4).
Table 23 describes sampling items and sampling areas. For surface monitoring, a total
area of wiping was 10 cm x 10 cm or the whole area of door handles, cabinet handles
or a spray gun handle.
Plate 15: GMD Systems Paper Tape and Permea-TecrM
Table 23: List of Items Used for Surface V/ipes and Approximate Areas Wiped
Items DescriptionBT Bench Top (100cm')
CB Chemical Balance (lOOcm'z)
RHM Rocker Handle in Mixing Room (66cm¿)
IDHM Inside Door Handle in Mixing Room (70cm'/)
ODHM Outside Door Handle in Mixing Room (70cm')
IDHB Inside Door Handle in Booth (98cm')
ODHB Outside Door Handle in Booth (98cm')
SIR Inside Surface of Air Purifoing Respirator (60cm')
SIAR Inside Surface of Hood-Airline Respirator (558cm2)
SOAR Outside Surface of Hood-Aidine Respirator (558cmz)
SG Spray Gun (99cm'z)
IG Inside Goggle (56cm'z)
OG Outside Goggle (56cm'/)
ST Sitting Table (100cm')
99
In order to measure exposure levels while using personal protective equipment (PPE),
the spray painters provided their respiratory protective equipment, rather than
providing overalls or disposable coveralls for assessment. None of the spray painters
used cotton gloves underneath the protective gloves. This investigation of PPE
contamination was conducted by wiping the inside and outside surface of respiratory
protection (a full face-air line mask or a half face respirator) used, after pure IPA was
sprayed. The outside surface of the respirator provided potential exposure levels from
air contamination and direct skin contact, and the isocyanate level on the inside
surface indicated the amount of leakage and facial exposure.
3.3.1.4 Dermal and ocular monitoring
Dermal monitoring was conducted by using GhostrM Wipe pads purchased from
Environmental Express (USA). Pure IPA was sprayed on the skin before the skin was
wiped by the Ghostru Wipe pads (see Section 3.4.4.1.4). For qualitative assessment of
skin contamination, commercial products (colorimetric Paper Tape and Swype Pads)
were also used. Figure 8 describes dermal monitoring areas for isocyanate (HDÐ.
ForeheadEye
Neck
Ii/ristFIand
Figure 8: Positions of Dermal Sampling
In particul ar, the commercial product (Permea-TecrM Pads¡ was attached to the
fingers and the hands under protective gloves before their application, to check for
100
isocyanate penetration to the skin through the glove material. Color change would be
observed, if there was the presence of isocyanates (e.g. HDD.
No sampling and analytical procedures for ocular monitoring of isocyanates are
currently available. However, ocular sampling was conducted using the same eye
drops (Allergan "Refresh") (see Section3.4.4.l.3), which were used for the pesticide
workers in 2001 and 2003 (Plate 11). Excess liquid from the comer of each eye was
absorbed on a sterile cotton swab. All the samples were collected immediately as soon
as the spray painters had finished the spray painting. Eye samples were then put in a
small vial containing 10 ml of the derivatizing solution.
3.3. 1.5 Biological monitoring
Biological monitoring for isocyanate exposure was considered, in particular HDA, but
for practical reasons including the cost associated with development of new method or
shipment overseas, it was decided not to proceed. Other researchers have utilized this
approach, but the relationship between HDA and inhalational exposure has not been
straightforward and there is no biological exposure standard based on urinary HDA at
present (Liu et a1.,2004).
3 .3 .2 Laboratory Methods
In order to develop sampling methods and analytical methods, there were a number of
optimization experiments carried out for denvatizing solutions and dissolving
solutions. For wipe sampling, GhostrM Wipes, Paper Tape and Permea-TecrM
Colorimetric Swlpe Indicators were tested for suitability. For testing glove
performance, a new test cell was developed for this study.
3 .3.2.1 Method development
3.3.2.1.1 HSE method (MDHS-2S, UK)
To determine exposure levels of workers handling isocyanate (HDÐ products and
peripheral surfaces, the basic methodology was to use a denvatizing reagent. The
advantages and disadvantages of selected reagents are summarizedinTable24.
101
Table 24: Reagent Systems for the Quantification of Airbome Isocyanates
Agents PrincÍple Advantages Disadvantages Reference
Marcali
Acid impinger/diazotizationwith nitrous acidand N-2-aminoethyl-l-naphthylamine
On-site colorimetricanalysis.Similar response
for polymericisocyanates
Only aromaticisocyanates.
Amine interferencemessy andinconvenient.Reagent potentiallycarclnogenlc.
NLI,2OOI
Ethanol
Impinger, formsurethaneanalyzablebyHPLC
Separation ofisocyanated(mainly monomers)
Only aromaticisocyanates (UVdetection)
NLI,2OOISkarping eta1.,1988
Nitroreagent
tN-(4-nitrobenzyl)-n-propylamine
I
Impingers/glasswool tube,forms ureaanalyzablebyHPLC
Separation ofisocyanates (mainlymonomers)Equalsensitivity forAliphatic andaromaticisocyanates
Less sensityve thanethanol for aromaticisocyanates.Reagent unstable HPLCcolumn degradation.
NLI,2001Corbini etal.,l99lHakes et al.,1986
MAMAte-(N-methy-aminomethyl)anthracene]
Impinger/hlter,forms ureaanalyzablebyHPLC.Isocyanatesidentified bydetector ratio(fluor/IJV)
Can quantifypolyisocyanates.Near universal IJVresponse factor.
Variable fluorescentyield per NCO.
NLI,2OOIAndersson elal.,1983Gudehn,1984
1-2MP
U-Q-methoxyphenyl)piperazinel
Impinger/filter,forms ureaanalyzablebyHPLC.Isocyanatesidentifred bydetector ratio(ECruV)
Can quantifypolyisocyanates
Analysis is morecomplex.EC detector unstable.
NLI,2OO1Schmidtkeand Seifert,1990Huynh et al.,1992NIOSH,1984b
1-2PP
lr-Q-pyndyl)piperazine]
Impinger/filter,foams ureaanalyzablebyHPLC.
Separation ofisocyanates (mainlymonomers)Filter option moreconvenient.
Pslyisocyanates stilldifhcult
NLI,2OOlEllwood etal.,l98l
Tryptamine
t2-(2-aminoethyl)indolel
Impinger, forms
Analyzable byHPLC.Isocyanatesidentified bydetector ratio(fluor/UV)
Can quantifupolyisocyanates.More constantfluorescent yieldper NCO.
EC detector unstable.Exposure hazard fromDMSO.
NLI,2001Wu et al.,1990
702
Table 24: Reagent Systems for The Quantification of Airborne Isocyanates(Continued)
The HSE (UK), MDHS-25 method using glass fibre filters impregnated with 1-(2-
methoxyphenyl) piperazine was used in conjunction with high perfoÍnance liquid
chromatography (HPLC) with ultraviolet (UV) and electrochemical (EC) detectors
(Pisaniello and Muriale, 1989a).
3. 3. 2. 1. 2 Sampling filter
According to the MDHS 2513 method (HSE, 1999), a glass fibre filter (25 mm) was
recommended for isocyanate sampling and should be impregnated before monitoring
a contaminated aÍea. When a denvatizing solution was prepared using l-(2-
methoxyphenyl) piperazine (1-2MP), 200 ¡r1 of the solution was dispensed on the
glass fibre filter - this was then dried out at room temperature under nitrogen.
MAP[9-(1-methylanthracenyl)piperazine]
Impinger/filter,foams ureaanalyzablebyHPLC.Isocyanatesidentified bydetector ratio(fluor/UV)
Can quantifypolyisocyanates.Near universal IJVresponse factor/sensitiveIJV detection.Compatible withPh gradient elution..
Variablefluorescent yieldper NCO.Stability of derivativesuncertain.MAP not commerciallyavailable.MAP artifact peaks.
NLI,2OOl
DBAIdibutylamine]
Impinger, forms
analyzablebyLC/MS.Isocyanatesidentified byMS.
Can quantifyisocyanates andamlnes.Faster reactiontimes.
Non-routine expensiveanalysis.
Quantiffingpolyisocyanates requiresstandards.
NLI,2OOI
PAC
[9-anthracenylmethyl-1-piperazinecarboxylatel
Inpinger, formsureaanalyzablebyHPLC.PAC derivativescan also becleaved tosingle product
No chromatographiclossesofisocyanatespecies.Simple chromatogram.No response factorvariability betweenisocyanates.
Impurities may givehigh blank of cleavageproduct.
NLI,2OOI
Iso-CheÉM
Combination ofPTFE(post-reactedwith 2-MP)andMAMA-dopedhlter.
Sêparates vaporand aerosol.Adopted byASTM.
Short-term sampling(l5min).Sample may not reactefficiently.
NLI,2OOl
103
3. 3. 2. 1 . 3 Abs orbing s o lution (D erivatizing So lution)
In order to maintain an excess of derivatizing agent in the denvatization of the
potentially larger amounts of isocyanate to be found in wipe samples (as distinct from
air samples), a higher concentration of 1-2MP (500 pglml instead of 50 pglml) was
required. The HSE method suggests using 1-2MP in dry toluene. However, it was
observed that not all 1-2MP readily dissolved at 500 pdml Methylene chloride was
tried as an alternative and the derivatising perfoûnance of l-2MP/methylene chloride
solutions were compared with l-2MP/toluene at the lower concentrations (see
3.4.4.1. 1 for results).
3. 3. 2. 1.4 Dissolving solutions
In order to improve the efficiency of dissolving the derivatized isocyanate (HDI),
methanol was compared with acetonitrile which is recommended by the HSE method.
A range of compositions of methanol in acetonitrile were used and analyzed with a
known amount of hardener solution (0.15 pgNCO/ml). The hardener solution was
transferred into small vials containing 10 ml of the derivative solution and analyzed
by using HPLC.
3.3.2.1.5 Ocular sampling solution ("Refresh" eye drops)
The suitability of Allergan "Refresh" eye drops for sampling isocyanate needed to be
checked. Technical grade hardener 10 pl (PPG, 2K MS Normal Hardener 980-35239)
was placed in "Refresh" eye drops (1.5 ml in a glass bottle). For comparison, the same
amount of hardener was applied to 1.5 ml pure toluene. A 10 ¡rl sample from each of
the two solutions was taken every minute and mixed with derivatising solution, and
processed in the normal way.
Isocyanates react with water, but this experiment would determine whether the
reaction rate was sufficiently slow to allow for ocular sampling.
104
3. 3. 2. 1. 6 GhostrM llipes
Following OSHA method No. W4002 (1999), 12 cm x 12 cm polyvinyl alcohol
GhostrM Wipes (Lawrence, 2002) were used for surface and skin wipes. (Plate 16)
Plate 16: GhostrM Wipe Pads
Before the Ghostrt Wip" pads were used in the field, their suitability was tested with
isopropyl alcohol wetting solutions þure and 50:50 water).
Known amounts of hardener (30 ¡r1 of PPG hardener) were applied to a clean glass
plate (10 cm x 10 cm). This pre-contaminated surface was sprayed up to 5 times with
IPA wetting solutions and twice wiped over using a dry GhostrM Wipe pad. Wiping
was carried out immediately and after set time intervals (1-3 minutes) before
denvatization. For sampling, tweezers were used to wipe across the surface several
times after applying IPA. HPLC was used to analyze the samples.
3.3.2.L7 Test cellfor glove perþrmance assessment
There is no standard test method to test isocyanate permeation rates and breakthrough
times for glove materials. V/ith this in mind, a simple disposable test cell for glove
performance was devised (see Figure 9) in a semi-quantitative methodology. The cell
comprised a glass cylinder (2.3 cm i.d.) and a rubber o-ring.
105
2.3cm
f\ -1
fIGlass Ware
Rubbm O-Ring
Glove lVfaterial
53cm
l,*Figure 9: Analytical Test cell
Glove permeation perfoflnance with respect to solvents present in the hardeners were
also tested using the conventional l" or 2" ASTM cells (see Chapter 2).
Finally, tests were done on gloves subjected to repeated washing (fatigue)
3.3.2.L8 Prepøration of the glove materials
Several kinds of glove materials were tested with technical grade hardener (PPG 2K
MS) and diluted (or working strength) hardener solution. Double layered Latex
Examination Gloves, Dermo PlusrM (cotton lined nitrile rubber, Ansell), Neoprene
Gloves (cotton lined, 29-865, Ansell) and Nitrosolve Gloves (Code No. 226836) were
tested. Plate 77 shows the gloves.
(Nitrile-Dermo Plus) (Neoprene) (NihoSolve) (Dispo. Nitrile-T.N.T.) (Dispo.Latex)
Plate 17: Glove Materials Used for Glove Performance Test
106
Procedures:
1. For isocyanate permeation tests, the glove materials were cut with > 4 cm diameter
A new analytical test cell was used for each sample.
2. For glove performance with component solvents, breakthrough times and
permeation rates were measured from sections of the palms and the arrns. Each part
was cut into 4.5 cm and 7 cm (diameter) for 1" and 2" ATSM test cells
respectively.A 1" test cell and a Photo-ionization detector (HNU P1 1010) were
used to detect the permeation of the solvent through the glove materials. Figure 10
illustrates of testing procedure for solvents.
{-Pump
FlowIvlelre
Battay
PhotoIomzationDetector
Tæt Cell(AS/I{ZS stendard 2 I 6 l. I 0. 3. 2û02)
Recorder
Figure 10: Instrumental Setup for the Detection of Solvent Breakthrough by PID
3. For the fatigue tests, new gloves (Nitrosolve Gloves; Code No. 226536) were put
into a washing machine. Warm water (60"C) was poured and then commercial
washing detergent (Approx. 110 ml) was added to each pair of gloves. The
washing machine was run for 20 minutes, and then rinsed with warm water (60"C).
After these procedures, the washed gloves were dried at room temperature for an
hour. In order to compare glove performance, four different types of gloves were
prepared, such as unwashed gloves and gloves washed between 1 to 3 times. The
disposable test cell was used for this test (see Figure 9). See also 3.3.2.2.4.
FFFt-rrE¡
107
3.3.2.2 Glove testing
3. 3.2.2. 1 Glove materials
Samples of the gloves were supplied by MSA (Aust.). Pty. Ltd., and provided by
individual industry and autobody shops. Each was visually inspected prior to use.
3.3.2.2.2 Permeation test of the glove materials
Isocyanates
For isocyanate permeation test using the disposable cell the bottom of the cylinder
was gently covered by a piece of the glove material without stretching. The challenge
hardener was PPG 2K MS Normal Hardener 980-35239 and a 50o/o solution in xylene.
The outer surface of the glove material was in contact with the test chemical, The
palms of the gloves were tested, because most of chemical was in contact with the
palm during spray operation rather than other parts. A rubber o-ring held the glove
material at t cm from the bottom of the test cell.
Colorimetric paper tape detection (GMD systems, aliphatic isocyanates) was used,
because it was easier and more economic, and provided more sensitivity than the
HPLC analyical method.
At regular time intervals (10 seconds, 1 minute, 5 minutes, 10 minutes and 20
minutes), pure IPA was sprayed onto the bottom of the surface, and then wiped with
the paper tape. As soon as the surface of the glove material was wiped, the tape was
dried with a hair dryer and the time was recorded. The reason for drying the surface
was to speed the colour change.
After the breakthrough times \¡/ere approximately determined with the paper tape
method, subsequent repeat evaluations were with GhostrM Wipe pads and pure IPA at
regular time periods. After wiping, the GhostrM Wipe pads were saturated with the
denvatizing solution, and analyzed by HPLC.
Component solvents
Organic solvents, such as acetone, xylene, isopropanol and toluene, were tested with
the selected glove materials.
108
A fully charged high capacity 6V lead acid battery was connected to a calibrated
pump providing constant air flow (100 mliminute) which was checked using an air
flow meter (see Figure 10). The photoionization detector was calibrated for each
solvent before use. The test material was prepared, and then put between two
compartments in the l" ASTM test cell. The outer surface of the glove material was
exposed to the challenge solvent. Air was supplied from the inlet tube to outlet tube at
the back part of the cell, and the contaminated air was run through the outlet tube,
which was connected to the photo-ionisation detector which indicate the detection of
solvents passes through the glove materials.
3.3.2.2.3 Breakthrough times and permeation rates
Permeation rates were calculated by the following equation based on ASÀ{ZS
standard 216l.10.3 (2002).
Here,
P : Permeation rate (p.glcmzlminute)
A: areaof the material specimen in contact in square centimeters ("*')
i : an indexing number assigned to each discrete sample, starting with i:l for
the first sample
Ti: the time at which discrete sample i was wiped in minutes (minutes)
C¡: the concentration of chemical in collecting medium at time T¡ in
micrograms per litre (þglmL)
V: total volume of dissolving solution (mL)
3. 3. 2. 2.4 Fatigue testing
In order to simulate normal usage, a washing machine was used to provide physical
stress to the glove structure.
109
MSA 226836, NitrosolverM gloves, often used by painters for mixing hardeners and
cleaning spray guns, were examined. However, disposable gloves (e.g. Touch N Tuff)
were used while spraying.
Pure technical grade hardener (PPG; 2K MS Normal Hardener 980-35239) and
diluted hardener at a working strength (resin:hardener : 2:1, 5Yo reducer) were tested
with the washed glove materials.
3.3.3 Analytical Methods
For skin and surface wipe sampling, pure IPA was sprayed onto the skin, a target
surface or the surface of PPE. The Ghosttt Wip" pads were used for wiping, and then
tweezers were used to pick up the pads so as not to contaminate the GhostrM Wipes.
During the sampling, clean disposable Nitrile gloves were wom. Wipes were put
directly into a vial containing 10 ml of derivatizing solution (500 ¡rglml 1-2MP in
methylene chloride). Sampling vials were stored in an icebox to be kept cold until
analysis and to be transported safely to the laboratory. After 24 hours, 200 ¡rl of acetic
anhydride was added into the vials, and they were left for 30 minutes to ensure the
completion of the reaction of the acetic anhydride with 1-2MP. Solutions were then
evaporated under nitrogen. The samples were then taken up in 10 ml acetonitrile
except in the case of eye samples, where 5 ml was used. For analysis, 20 p,l of the
solution was injected into the HPLC.
The HPLC operating conditions were based on the HSE method (MDHS, 2513,1999)
and previously reported (Pisaniello et a1.,1989a). An ICI Instruments LC 1500 HPLC
Pump, TC 1900 HPLC Temperature Controller, BAS LC4BILCITA Amperometric
Detector, Kortec K95 Variable 'Wavelength UV/EC Detector, DP 800 Data Interface,
and a 25 cm x 4.6 mm Spherisorb ODS2 (Cl8) Column) were used.
The conditions of HPLC were 30oC (oven temperature), 1.5 ml/minute (pump rate),
0.8 V (EC detector) and 242 nm for an UV detector. The mobile phase was 67%o
acetonitrile,33yo distilled water and pH 6.0 (acetate buffer). Helium gas was bubbled
through the mobile phase.
110
Monomeric and polyrneric isocyanate were detected most commonly at 3.08 minutes
and 7.8 minutes respectively.
3.3.4 Limits of Detection
The limit of detection was 0.003 ¡rgNCO/ml for the EC detector which is more
sensitive than the UV detector (0.008 pgNCO/ml).
The sensitivities of the self-indicating paper tape and Permea-TecrM Swype Pads
(approx. 0.002 pgNCO/ml) were greater than that of the HPLC method, and in some
cases, dilution was required.
Using a Photo Ionization Detector, the detection limits of acetone, isopropanol and
xylene were 1 ppm, and for toluene, the limit of detection was 3 ppm.
3.4 Results
3.4.1 Work Practices
Spray painters in the crash repair workshops somtimes wore disposable latex gloves,
full-face airline respirators, disposable coveralls and safety goggles. However, most
wore only overalls and half face respirators.
Even though the spray painters wore their PPE during working hours, the PPE was not
washed frequently, or did not get washed for a long period of time, in particular full-
face airline respirators, helmets and half face respirators. In addition, the respirators
were not stored in an airtight containers to protect the charcoal filters from other
organic solvents in the air.
It was observed that clothing was occasionally contaminated, and skin/eyes were
sometimes contaminated by deposited spray mist. 'Whenever they were mixing or
spraying, several workers folded their sleeves up to the elbows, and the front of their
overalls were open. The workers had potential exposure via deposition on their skin or
clothing, such as the head, neck, face, eyes, hands and arms from handling hardener
during spraying, mixing and cleaning. When they finished the spray painting, they
touched contaminated surfaces (e.9., full face/half mask, overalls, mixing table and
spray gun) with their hands without wearing protective gloves.
111
After the spray application, spray guns were somtimes rinsed with acetone. During the
rinse process, there was no dermal, eye or respiratory protection worn. In the mixing
room, bench tops and floors were frequently not cleaned after mixing hardener, even
though it was obvious that there was hardener spilled.
In the furniture industry, the spray painters, including a spray paint mixer, wore
disposable nitrile gloves (Touch N tuffrM), disposable overalls (spray painters only)
and half face respirators (spray painters only) during working hours. However, they
did not ìù/ear appropriate eye protection, and wore nonnal sports shoes as foot
protection. Their lower arms, head, neck and chest were not protected by any PPE.
Even though the spray painters used a respirator, the mask was stored or put in a
contaminated area without cleaning after the spray painting. Sometimes, their
disposable nitrile gloves were physically damaged, and a small hole was observed,
because they touched or handled wood panels or small pieces of wood.
The spray paint mixer handled hardener containers and solvent containers. He also
used acetone to rinse or clean the top of the automatic spray gun with the index and
middle fingers being swollen by solvent contact. In the mixing room, spills of solvents
and hardeners were observed.
The spray painters were oxposed to isocyanate vapors and mists in the spray booth,
even though the isocyanate concentration of hardener was lower than in the vehicle
crash repair shops. In the manual spray booth, the spray painters sprayed about 2 m
away from the extraction vent.
In the storage room, the ventilation system appeared to be poor as significant solvent
odors could be detected.
3.4.2 Survey Results
3.4.2.1Subjects
Table 25 shows personal baseline data and the prevalence of previous health
symptoms from the exposed group and the unexposed group. For the two groups, the
average age and smoking prevalence were similar.
112
Exposed (¡=33)* Controls (n:91)
Mean Age (STD)(years) 28 (!12) 38 (re)
Current smokers 1s (46%) 43 (47%)
1-5 per day r (3%) 7 (8%)
6-10 per day 3 (e%) 7 (8%)
I 1-15 per day 2 (6%) 7 (8%)
16-20 per day 3 (e%) 12 (r3%)
> 20 per day 6 (18%) 1o (11%)
Ex-smokers s (15%) 12 (t3%)
Ever had hayfever? rt (33%) 3s (3e%)
Ever had asthma? 7 (21%) 7 (8%)
Ever had eczema2 2 (6%) s (6%)
More severe reaction thanothers to insect bites
2 (6%) 1 (8%)
Table 25: Baseline Variables for HDI Spray Painters and Controls#
# All males, Study Group 3 only
No statistically significant difference in proportions between exposed workers and controls (p < 0,05, two-tailed test,)(Fleiss,1981)
There were no statistically significant differences for hayfever (33% vs 39yo), asthma
(21% vs 8olo), eczma (6Yo vs 60/o), dermatítis (24Yo vs l2%o) and more severe reactions
than others to insect bites (6% vs 8%).
Information on hardener usage and application among HDI spray painters is described
in Table 26. The average usage of HDI based paint was 0.8 L for 2.2 hows per day.
During working hours, 46%o of spray painters reported that they had sprayed outside a
spray booth. Out of hours (hobby) spraying was repodedby 24% of workers.
Table 26: Chemical Usage and Application Among HDI Spray Painters
Spray painters (n=33, males)
Use amount of chemical (average) 0.8 L/dav
Application hours (average) 2.2hours/day
Outdoor spravins durine working hours? rs (46%\
Spraying outside of regular working hours? 8 (24%)
113
3.4.2.2 Symptom prevalence
Table 27 gives the s5rmptom prevalence data derived from the questionnaire survey.
Table 27: Work-related Syrnptom Prevalence Data (HDI Spray Painters)
* Statistically differeut proportions from controls (p < 0.05, two-tailed test,) were indicated (['leiss, 1981)
# All males
The main adverse symptoms were the skin symptoms, pulmonary symptoms and
headaches.
Of the 16 people with phlegm problems, 13 people reported that they had more
syrrìptoms in the moming.
Among the exposed, pulmonary symptoms were often attribributed to smoking,
asthma, hayfever and chemical mists and vapors from spraying.
Svmptoms Exposed (n=33) # Non-exposed (n:91) #
Skin symptoms
Dry cracked skin 20 (61%). t7 (re%)
Skin rash 4 (12%) s (6%)
Dermatitis/skinirritation
tt (33%)' 4 (4%)
Pulmonary symptoms
Coueh t3 (3e%) 2t (23%)
Morning 6 (18%) 13 (14%)
Day
Nisht
6 (t8%) 3 (3%\
t (3%) s (6%)
Phlesm 16 (4e%). 24 (26%)
Morning t3 (3e%) 22 (24%)
Dav 0 (0%) o (o%)
Nieht 3 (e%) 2 (2%)
Increasedcoush/phlesm
s (ts%) L4 (ts%)
Shortness ofbreathwith wheezins
10 (30%) 2t (23%)
Chest tight/breathingbecome difficult 10 (30%) t8 (20%)
Eve svmptoms
Eye irritation 3 (e%)' 24 (26%)
Itchv eves 4 (t2%). 26 (2e%)
Dry eyes 4 (12%) ts (r7%)
Coniunctivitis 2 (6%) 2 (2%)
Others t (3%) 3 (3%)
Headaches t6 (4e%) 36 (40%)
Blackouts t (3%) 0 (0%)
tt4
Eye symptoms, except for conjunctivitis, were relatively uncommon among spray
painters. Only four of the exposed group reported itchy eyes, but of these three were
apprentices.
A greater prevalence of headaches was reported from the exposed group (49%),
compared with the unexposed group (40%). There was no reason given for the causes
of the headaches for the exposed group, although it is possible solvent or thinner
exposure may have been a factor.
The question on "Blackouts" was used to check on over-reporting of syrnptoms by the
interviewee. As in the pesticide study, over-reporting of syrnptoms did not appear to
be an issue.
3.4.2.3 Accidental exposures
Table 28 gives the accidents caused by chemical use, and it can be seen that 42o/otrad
an experience of a major spill (> 500 ml). Eighty five percent had experienced a
splash on the body, due to chemical liquid leakage from spray guns, chemical spillage
from mixing, chemical splash from washing/cleaning equipment etc. Whlle 72Yo
reported using eye protection, 42Yo had experienced a splash in the eye. People who
reported wearing safety goggles or full face-airline respirator (see below) did not
suffer from a splash to the eyes.
Table 28: Accidents from Chemical Use Among HDI Spray Painters
3.4.2.4 Use of personal protective equipment
Table 29 gives information on PPE usage. The main PPE used were full-face airline
respirators (33%), half face-airline respirators (18%), hood or helmet-airline
respirators (I8%), half face cartridge respirators (73%), overalls (61%), disposable
Spray painters (n=33, males)
Maior spill (>500 ml) t4 (42%)
A splash in eyes 14 Ø2%)Splashing any other part ofthe body 28 (85%)
Accident free from spill and splash 2 (6%)
115
coveralls (49%), safety glasses including prescription lenses (I2%), safety goggles
(9%) andprotective gloves (46%).
Table 29: Use of Personal Protective Equipment Among HDI Spray Painters
Items Spray painters (n=33, males), 7o prevalence
PPE usage
Full face-airline respirator tr (33%)
Half face-airline respirator 6 (r8%)
Hood or helmet-airline respirator 6 (t8%)
Air purifying cartridge respirator 24 (73%)
Overalls 22 (61%\
Disposable coveralls 16 (4e%)
Glasses (prescription lenses) 4 (12%)
Goggles 3 (e%)
Face shield 0 (0%)
Protective gloves ts G6%\
Protective Gloves l)
Twe of gloves
Cotton o (o%)
Disposable latex examination e (27%)
Disposable rubber 0 (0%)
Disposable nitrile 3 (e%)
Disposable vinyl 3 (e%\
Leather o (o%)
Neoprene 18 (55%)
Nitrile 0 (0%)
Nitrosolve 0 (0%)
PVC 0 (0%\
Replacement of gloves
Everytime tr (33%)
Every day 2 (6%)
l/lVeek 3 (6%)
Foot protection
Shoes 1(2t%)Boots 2s ('76%)
Cleaning
Shoes s (ts%)
Overalls t4 (42%)
Respirator 2r (64%)
Remove overalls at lunch break ts (46%)
Remove overalls before going home 26 (7e%)
1) More thân one glove were used by subjects
11ó
Of the protective gloves, the main types of gloves used were disposable latex (27Yo),
disposable nitrile (9%), disposable vinyl (9%) and neoprene (55%). However, for
spray painting, disposable latex examination gloves were mostly used in the crash
repair shops. Neoprene gloves were used for cleaning spray guns after the spraying
painting. In the case of disposable gloves, the gloves were replaced every time (within
20 minutes as maximum). Several workers used more than one type of glove for
different pu{poses on the same day, such as spraying paints and cleaning or washing
equipment.
For foot protection, ofthe exposed Broup, 2l%oused sports shoes and760/o used safety
boots during working hours. However, since they were provided with safety boots or
they had bought a new pair of safety boots, they used the same safety boots without
cleaning or replacement. In the case of sports shoes, overalls and respirator, the
percentages of use were I5o/o, 42o/o and 64Yo respectively. Sports shoes and overalls
were cleaned once a week or two weeks. The respirator was often kept in
contaminated areas, such as bench tops or the floor. Not everyone cleaned their
respirator every time or daily.
At lunch breaks, 460/o removed overalls. Seventy nine percent of the exposed group
removed contaminated overalls before going home.
3.4:2.5 Knowledge and training
Table 30 gives the survey results for knowledge and training among the exposed
goup.
Table 30: Training and Education among HDI Spray Workers
Spray painters (¡:33), 7o prevalence
Formal training in use 28 (8s%)
Period of trainins
I day course 0 (0%)
> 2 days course 28 (8s%)
Education
Health effects 27 (82%)
PPE usage 29 (88%)
MSDS 24 (73%)
tr7
A high proportion of the spray painters had attended formal training program (85%)
about using isocyanates (e.g. HDI). Of the 33 spray painters, 28 (85%) had more than
a 2-day training course. In the case of education about health effects, PPE usage and
MSDS, 82yo,88yo andl3Yo were reported respectively to have had such training.
3.4.3 Environmental Measurements
3.4.3.1 Study group 3
3.4. 3. 1. 1 Observations
The spray painting was norrnally conducted inside a downdraught or lateral flow
spray booth.
3.4. 3. I. 2 Air monitoring
Air monitoring was conducted for the spray painters performing the 2-pack spray
painting to determine air contamination levels inside and outside spray booths.
Impregnated glass fibre filters were attached within the breathing zone of the
operators during the spray painting.
3.4.3.1.2.1 Spraying in a booth
The spray painting was carried out inside the spray booth with the temperature
controlled by an auto heating system at about 30oC. Table 31 gives the personal air
monitoring results of the spray painters during the spray painting conducted inside the
spray booth.
The maximum sampling time was 20 minutes. In general, a small part of a vehicle
needed to be sprayed and the application time of the 2-pack spray was 15 minutes. A
high volume low pressure (HVLP) spray gun was mostly used for the spraying inside
the booth. The level of air contamination was usually lower than the STEL (0.07
mgNCO/m3 in 15 minutes), except for 55 and S8. In the case of study subjects 35 and
38, 55 placed his head next to the area being painted in order to check the surface
during the spraying and S8 was close to the area being sprayed.
118
Without an extraction system, the lowest and the highest levels of air contamination
were 0.55 mgNCO/m'lSta; and2.4 mgNCO/m3 lStl¡ respectively. These are much
higher than the STEL.
Table 31: Personal Isocyanate Exposure Concentrations of Spray Painters InsideSpray Booths within Breathing Zonein Study Group 3
All subjects were touch up spray painters, GM: geometric mean
<0.03 pgNCO; limit of detection, Exposure limits (STEL): 0.07 mgNCO/ml
@ Sprayed in a dedicated spray booth with an extraction system
# They were not in a dedicated spray booth, but a ventilated room. Extraction system was not turned on.
3.4.3.1.2.2 Spraying outside of the booth
Personal and fixed position air samples were collected from outside spray booths or in
the general areaîeat touch spraying that was not conducted in a dedicated booth.
Workshop employees in the general area were fitted with personal monitors and
measurements were taken when spraying was conducted in the booth by another
worker.
I.D.
Extractionsystem
(Yes/l{o)
Totalisocyanate(usNCO)
Samplingtime
(minute)
Total airvolume
(L)
Isocyanate conc.(mgNCOim3)
s3@ Yes 0.12 2 2 0.06
s4@ Yes 0.06 J J 0.02
s5@ Yes 3.42 4 4 0.9
s6@ Yes < 0.03 4 4 < 0.008
s8@ Yes 0.62 7 7 0.09
sl0@ Yes 0. t7 15 15 0.01
s16@ Yes 0.14 l8 18 0.008
sl7@ Yes 0.06 20 20 0.003
AM t STD
(GM)
0.14 r 0.3
(0.024\
s 18# No 1.09 2 2 0.55
sl9# No 7.23 J J 2.4
s20# No 3.42 4 4 0.86
AM f STD
(GM)
1.3 + 1.0
(1.04)
119
Table 32 shows undetectable levels of isocyanate in various situations. This indicates
that isocyanate leakage from the booth is negligible.
Table 32: Personal and Fixed Position Isocyanate Concentrations Outside SprayBooths in Study Group 3
<0,03 ¡rgNCO; limit of detection,
a: Personal measurements for workshop employees, when spraying was conducted in the dedicated boothb: Mobile spray painter (Sampling at 3-4 m away from the spray spot),c: Mobile spray painter (Sampling at 4-5 m away from the spray spot),
3.4.3.1.3 Dermal and surface monitoring
The Ghostrt V/ip" pads were used for skin sampling and either the paper tape or
Permea-TecrM pads were used for surface monitoring. Pure IPA was sprayed on a
target area and then the area was wiped with the GhostrM Wipe pads for both indoor
and outdoor spray painting. Several parts of the painters' body were wiped after the
spray application, such as the neck, hands, wrists and forehead. Spray application time
was between 1- 20 minutes. For surface monitoring, a wide range of surfaces were
selected, such as chemical balances, bench tops, door handles and spray guns.
3.4. 3. 1.3. I Indoor spraying
Skin wipe samples were collected as soon as they had finished the spray application
inside the dedicated spray booth. Table 33 gives the results of skin surface monitoring
with GhostrM'Wip"s.
I.D.Total isocyanate
(pgNCo)Sampling time
(minute)
Total airvolume
(L)
Isocyanate conc.(¡rgNCO/m3)
s2l" < 0.03 2 2 < 15.00
s22^ < 0.03 4 4 < 8.00
s23' < 0.03 20 20 < 2.00
s24u < 0.03 30 30 < 1.00
s25^ < 0.03 50 50 < 1.00
s26u < 0.03 60 60 < 1.00
Glb < 0.03 2 2 < 15.00
G2' < 0.03 60 60 < 1.00
t20
Table 33: Isocyanate Dermal Monitoring of Indoor Spray Painters in Study Group 3
*S1, 57, S1l, S12: Apprentices from MTA and training school (TAFE)
<0.03 pgNCO; limit of detection,
N;Necþ LBH: Left back hand, RBH: Right back hand, LP: I,eft palm, RP: Right palm, FH: Forehead, LW: Left wrist,RW: Right wrist,
a: Wore disposable latex gloves,b: Wore disposable nitrile gloves,c: No protection,d: Wore full face-air lined masþc: Wore disposable coverall,f: Covered by disposable overall,g: Touched by contaminated hands
When the spray application time was greater, more isocyanate was detected on the
skin, as is the case for S12 who incidentally did not wear personal protective
equipment. Not surprisingly therefore, S12 gave the highest quantities of isocyanate.
In general, the apprentices had higher exposure levels than the experienced spray
painters, and painters who wore body protection and gloves had lower exposures.
Several spraypainters (S3, S7, 58, 59 and S11) used disposable latex gloves giving
exposure levels up to LBH (57-0.15 pgNCO), RBH (S11-0.48 pgn\Co), LP (51-0.42
I.D.Samp.time
(minute)
Total isocyanate (pgNCO)
N FH LBH RBH LP RP L\il RW
S2 I < 0.03" < 0.03 " < 0.03 b < 0.03 b < 0.03 b < 0.03 b < 0.03 f < 0.03 f
S3 2 < 0.03" < 0.03 " 0.06 u < 0.03 u 0.09 "< 0.03 u
< 0.03 " < 0.03 "
S4 J 0.09 " 0.09 " 0.17' < 0.03 " 0.09 " 0.11" l.g5 " < 0.03"
S5 4 < 0.03" < 0.03 " 0.05 " 0.04 " 2.03' 0.ll " 0.14' 0.06 "
S6 4 0.09s 0.11e < 0.03 " < 0.03 " < 0.03 " < 0.03 " < 0.03 " < 0.03"
S8 7 < 0.03e < 0.03 " < 0.03 u < 0.03 u 0.05 " 0.04 " 0.04 " < 0.03"
S9 9 0.31s < 0.03s < 0.03 u 0.19 u 0.18 " < 0.03 u 0.06 " 0.09 "
sl0 15 0.13 " 0.30 " 0.09 " 0.05 " 0.01 ' 0.15 " 0.r2' 0.27'
AMTSTD0.08
+0.100.07
+0.100.05
10.050.04
+0.060:32
r0.690.06
10.060.29
!0.610.06r0.09
s1* I < 0.03e < 0.03 " 0.25' 0.19 " 1.23 " 0.72' < 0.03 " < 0.03"
S7 5.3 0.19e 0.1I " 0.15 u 0.1 u 0.42 u 0.39 " 0.5 " 0.17 "
sl1* 25 0.2 " < 0.03d < 0.03 " 0.49 u 0.1u 0.49 u 0.43 " 3.05 "
s 12- 30 1.53" 2.46 " 2.53 " 2.62 " l.69' 2.16' 2.72 " 2.13'
AMTSTD0.63
+0.680.65
+1.210.14r0.12
0.8511.19
0.86t0.73
0.94r0.83
0.92+1.22
1.34
+1.49
t2t
pgNCO) and RP(SI1-0.48 pgNCO). Screening with skin SWYPESTM, underneath the
disposable latex, yieled a color change,
After the spraying, the behaviors of workers were observed. 56 and 59 had
contaminated hands after finishing the spraying and transfer occurred, thus the
exposure levels of the neck and the forehead were 0.3 1 pgNCO (S9) and 0.1 I ¡rgNCO
(56) respectively. 56 had low levels of exposure, except for his neck and forehead,
because he used a lower concentration of hardener (3% of isocyanate) for the 2-pack
spray painting than the normal 2-pack spray painting (30% of isocyanate in liquid
hardener).
3.4.3.1.3.2 Outdoor and mobile spraying
For the outdoor and mobile spray painters, skin exposure levels were measured after
they finished the spray application. Table 34 gives the results of dermal monitoring.
Table 34: Isocyanate Dermal Monitoring of Outdoor/Mobile Spray Painters in StudyGroup 3
All subjects were doing touch up spray painting except S15.
<0.03 pgNCO; limit of detection,N;Necþ LBII: Left back hand, RBH: Right back hand, LP: Left palm, RP: Right palm, FH: Fore head, LW: Left wrist,R\{: Right wrist,
a: Outdoor sprayer,b: Mobile sprayer,c: Wore disposable nitrile gloves,d: No protection
S14 had the highest skin exposure. He was significantly closer to the spray surface,
spray mist was visible and there did not appear to be sufficient air movement.
I.D.Samp.time
(minute)
Total isocvanate (ueNCO)
N F'H LBH RBH LP RP LW R\il
s13 u 2.4 0.54 d 0.19 d < 0.03" < 0.03" < 0.03 " < 0.03 " < 0.03d 0.06 d
s14 " t.J 0.35d 0.54 d 0.80 d 1.08 d l.g3 d 2.59d < 0.03d < 0.03d
s15 b 3t < 0.03d < 0.03d 0.08 d 0.07 d 0.06 d < 0.03 d < 0.03d < 0.03d
AMlSTD0.30x0.27
0.25
!0.210.30x0.44
0.39+0.60
0.64
r1.040.88
r1.480.02
r0.000.03
r0.00
122
3.4. 3. 1. 3. 3 Surface monitoring
Qualitative (Permea-TecrMl and semi-quantitative (GhostrM Wipe) surface monitoring
were conducted. Table 35 gives the monitoring results, and suggests that many of the
surfaces were contaminated, including the door handles.
Table 35: Quantity of Isocyanate on Surface Samples in Spray and Mixing Areas inStudy Group 3
<0.03 pgNCOicmt & <0.03 ¡rgNCO; limit of detection,
CB: Chemical balance, BT: Bench top, RHM: Rocker handle in mixing room, IDHM: Inside door handle in mixingroom, ODHM: Outside door handle in mixing room, IDHB: Inside door handle in spray booth, ODHB: Outsidcdoor handle in spray booth, SG: Spray gun,
a: Containing high level of hardener (-300 g/L),c: \iliped after spray application each time.,e: During lmin,g; During 4min,i: During 7min,k: During 7.3min.
b: Containing lowest level of hardencr (48 CIL),d: During 25min,f: During 15min,h: During 2min,j: During 4min,
Two kinds of different hardeners were used for this monitoring. The high level
hardener contained around 30Yo of isocyanate and the lower level of hardener
contained around 3%o of isocyanate at 88. B8 used the lower level hardener and no
isocyanate (HDI) could be detected in any of the samples.
I.D.
Isocyanate conc.(ueNCo/cm2) Total isocyanate (pgNCO)
CB BT RHM IDHM ODHM IDHB ODIIB SG"
Blo 0.05 < 0.03 < 0.03 < 0.03 < 0.03 4l.l < 0.03 2r.fB.2u < 0.03 < 0.03 < 0.03
83u 0.1 1.2 0.4"
P'4u < 0.03 < 0.03 < 0.03 < 0.03 1.6 0.5 10.5f
85u < 0.03 0.04 < 0.03 0.28
86u 0.12 0.04 0.04 0.3h
BJU < 0.03 < 0.03 < 0.03 < 0.03 0.3 0.1 < 0.03'
Bgb < 0.03 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03r
Bgu 0.05 0.9 4.6k
AMISTD0.04
+0.040.02t0.02
0.02r0.00
0. 13
+0.290.11!0.42
10.9
r20.540.16.0.23
4.64+7.60
t23
In the case of spray guns, B I had the highest level of exposure (21 . 1 pgNC O) after 25
minutes. In the case of 84, the spray painter cleaned the surface of the chemical
balance in the mixing room after each use resulting in no detectable isocyanate.
Table 36 gives the surface results, when using qualitative colorimetric tape or Swype.
The results were described as positive and negative. If there was isocyanate, a positive
(P) result was recorded, otherwise a negative (N) result was recorded. Even though
there were positive results from the surface monitoring (81-BT, IDHM, ODHM and
ODHB, B2-CB, IDHM and ODHM, B4-BT and B7-IDHM), they were mostly under
the limit of analytical HPLC detection.
Table 36: Isocyanate Indicator Paper Testing of Surfaces at Automobile Shops byUsing Paper Tape or Permea-Tectt Pudr in Study Group 3
I.DColor reaction (P:positive. N:nesative)
CB BT IDHM ODHM IDHB ODHB
B1 P P P P P P
B2 P P P P
B3 P P P P P
B4 NU P P P
B5 P P P Nb
B6 P P P P
B7 P P P Nb
B8 P P Nb Nb
B9 P P P P P P
CB: Chemical balance, BT: Bench top, IDHM: Inside door handle in mixing room, ODHM: Outside door handle inmixing room, SIRM: Surface of inside rcspiratory masþ IDHB: Inside door handle in spray booth, ODHB:Outside door handle in spray booth, SG: Spray gun,
a: Clean after use,b: Open all the time without touching.
3.4. 3. 1.4 PPE monitoring
PPE monitoring was carried out to detect possible contamination in terms of work
practices. For this monitoring, the same sampling procedures were used as for surface
monitoring.
124
3.4.3. 1.4. I Indoor spraying
The indoor spray painters used either a full-face air line respirator or a half face
respirator for organic solvents and isocyanate. The respiratory protective equipment
was tested after the spray application. Table 37 gives the monitoring results for PPE
after the indoor spraying.
Table 37: Isocyanate Contamination Levels of Personal Protective Equipment (PPE)
for Indoor Spray Painters in Study Group 3
<0.03 pgNCO; limit of detection,*Sl, 37, S12: Apprentices from MTA and training scltool ([AFE),
SIAR: Inside surface of full facc air line rcspirator, SOAR: Outside surface of full face air line respirator, SIR: Insidesurface of air purifying respirator
a: Not cleaned before and after use, and stored in contaminated areab: Poor facial fÌt, due to beard and different size,
c: Touched by contaminated hands, and stored in contaminated area
The highest levels of HDI inside and outside full-face air line respirator were 2.8
FSNCO arLd2l.8 pgNCO respectively. From the inside the half face respiratory mask,
the highest level detected was 2.6 pgNCO (S3). In the case of 52 and 53, they stored
the respirator in a contaminated area and the respirator were kept in a container with
no appropriate isolation from solvents.
I.D.Total isocyanate (peNCO)
SIAR SOAR SIR
S2 2.9 u
21.8
S3 2.60^
S4 0.0g b
S5 < 0.03 b
S6 < 0.03 b
S8 0.01^
S9 0.96 u
s10 < 0.03 b < 0.03
AMTSTD 0.61 I 1.0
s1* 0.44 " 9.0
s7- 1.61 " 9.0
s l2- < 0.03 < 0.03
AMISTD 0.69 r 0.83 6.0 t 5.2
125
It was found that the inside of the respiratory protective devices were contaminated by
isocyanate in most cases. From 54, 55 and 56, it was observed that the fit of the
respiratory mask was poor, due to facial hair. In the case of 57, 1.61 pgNCO was
detected from the inside respirator. During and after spray painting, the sprayer (S7)
touched the inside the respirator with contaminated hands while doruring and taking
off the respirator. In general, it was shown that the exposure levels on the outside of
the respirator were over ten times higher than the inside levels.
3.4.3.L4.2 Outdoor and mobile spraying
Spray painters using safety goggles and respirators were tested. The inside of the
goggles and respirators were wiped. The results were described in Table 38.
Table 38: Isocyanate Exposure from Personal Protective Equipment (PPE) forOutdoor/Mobile Spray Painters in Study Group 3
# All subjects were touch up spray painters
<0.03 pgNCO; limit of detection
IG: Inside safety goggle, OG: Outside safety goggle, SIR: Inside surface of half mask air puifying respirator
a: Not cleaned before and after use, and stored at contaminated area without storing in evacuated container
All goggles and masks were stored in contaminated areas and not cleaned before or
after spray painting. The inside of the safety goggles gave up to 0.14 pgNCO, and
1.17 ¡rgNCO was detected inside the respirator. The mobile spray painter used a half
face respirator.
I.D.#Total isocyanate lueNCO)
IG OG SIR
s13 0.14 " 0.97 0.53 "
s14 l.l7 ^
s15 0.07 u< 0.03 < 0.03 u
AMTSTD 0.57 + 0.58
t26
3.4. 3. 1. 5 Ocular monitoring
Ocular monitoring was conducted to examine whether potential eye problems could
occur. The left eye and right eye were measured separately, and eye protection was
also checked. Application times for the spray painting ranged were between 1-20
minutes.
3.4.3. 1. 5. I Indoor spraying
Ocular sampling results are given in Table 39. The results are divided into two parts,
i.e. one group wearing no eye protection (S1-S5) and the other group wearing eye
protection (56-5 l2).
Table 39: Isocyanate Ocular Exposure for Indoor Spray Painters in Study Group 3
* 51, 57, S11, S12: Apprentices from MTA and training school (TAFE),
N,D.: Not detected; <0.02 pgNCO; limit of detection
In the case of S1 (an apprentice), the right eye had 0.25 ¡rgNCO. From the group
wearing eye protection, there was no detectable isocyanate except for S11 and S12,
observed to be due to touching of their eyes with contaminated hands after the spray
painting.
I.D. Eye protectionTotal isocyanate ([sNCO)
Left eye Rieht eye
S2 None 0.02 0.03
S3 None N.D N.D
S4 None N.D N.D
S5 None N.D N.D
S6 Full face air line mask N.D N.D.
S8 Full face air line mask N.D N.D
S9 Full face air line mask N.D N.D
S1 None 0.0s 0.25
s7" Full face air line mask N.D N.D
sll Full face air line mask 0.1 N.D
s 12* Full face air line mask N.D 0.18
I2l
3.4.3.1.5.2 Outdoor and mobile spraying
Ocular isocyanate exposure was measured for outdoor and mobile spray painters and
given in Table 40.
Table 40: Isocyanate Ocular Exposure for Outdoor/Mobile Spray Painters in StudyGroup 3
#All sub.iects were touch up sprây painters
N.D. <0.02 pgNCO; limit of detcction
a: No protection, b: Wore safety goggle
S13 did not wear any eye protection . There was no significant exposure for S14 and
515 who wore safety goggles.
3.4.3.2 Study group 4 (Furniture spray painters)
3. 4. 3. 2. I Obs ervations
When the door of the manual spray booth was closed, the extraction system on the
ceiling did not appear to be working properly. The air flow rates at 1 m from the
extraction system were between 0.1-0.2 m/second using a hot-wire anemometer, but
at 2 m away from the extraction system, no air movement was observed using a
smoke tube.
3.4. 3. 2. 2 Air monitoring
Personal monitoring of spray painters and a spray paint mixer was carried out. They
used hardener with less than 2o/o isocyanate.
Table 41 gives personal air monitoring results indicating insignificant exposure.
I.D.#Total isocvanate (ueNCO)
Left eye Rieht eve
s13 u 0.05 0.02
sl4 b N.D. N.D
s15 b N.D. N.D.
128
I.D.#Total isocyanate
(pgNCo)Sampling time
(minute)
Total airvolume
ú)Isocyanate conc.
(pgNCO/m3)
Fl , < 0.03 18 20 < 2.00
F3' < 0.03 200 200 < 1.00
F20 < 0.03 156 160 < 1.00
F20 < 0.03 390 390 < 1.00
Tablç 41: Personal Isocyanate Exposure Concentrations of Spray Painters InsideSpray Booth in Study Group 4
#All subjects were touch up sprây painters (i.e. re-spraying imperfections in the manual booth)
<0.03 pgNCO; Iimit of detection,
a: Spray painter working inside the bootltb: Spray paint mixer working in mixing area,
Table 42 gives isocyanate results for fixed positions which were away from the spray
booth. Monitoring locations were beside the spray booth (the mixing area) and the
middle of the work area located over l0 m away from the spray booth. No isocyanate
was detected.
Table 42: lsocyanate Exposure Concentrations in General Area in Study Group 4
<0.03 pgNCO; limit of detection,
a: Sampling at collecting room beside the spray booth'b: Sampling outside the spray bootlt.
3.4.3.2.3 Dermal and surface monítoring
There were several types of monitoring, i.e skin monitoring, surface monitoring and
qualitative hand monitoring.
Table 43 gives the skin monitoring results for the spray painters and mixer. No
isocyanate could be detected on the skin, probably due to the low isocyanate
concentration in the hardener.
I.D.Total isocyanate
(¡rgNCo)Sampling time
(minute)
Total airvolume
tL)
Isocyanate conc.(pgNCO/m3)
A1 u < 0.03 440 440 < 1.00
A2b < 0.03 44s 445 < 1.00
A3b < 0.03 44s 445 < 1.00
t29
I.D.#
Samp.time
(min)
Total isocyanate (pgNCO)
N FH LBH RBH LP RP LW R\ry
FI 4 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03
F2 240 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03
F3 525 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03 < 0.03
Table 43: Isocyanate Dermal Monitoring of Spray Painters in Study Group 4
#All subjects were touch up spray paintcrs (i.e. re-spraying imperfections)
<0.03 pgNCO; limit of detection,
N;Nect<, LBH: Left back hand, RBH: Right back hand, LP: Left palm, RP: Right palm, FH: Forehead, LW: Left wrist,RW: Right wrist
Table 44 gives the monitoring results of surface samples. Door handles of the spray
booth did not show any contamination of isocyanate (HDI), and no isocyanate was
detected on the spray gun, which was wiped as soon as spray painting was finished.
Table 44: Quantity of Isocyanate on Surface Samples at Spray and Mixing Areas rnStudy Group 4
#Monitoring relates to touch up spray painters (i.e. re-spraying imperfections)
<0.03pgNCO; limit of detection,
SG: Spray gun, IDHSB: Inside door handle at spray bootlr, ODHSB: Outside door handle at spray bôoth
Table 45 gives the monitoring results of isocyanate penneation through the disposable
nitrile gloves (Touch N Tuff).
The Permea-TecrM Pads were attached on the palms and index fingers. There was no
isocyanate penetration through the gloves after 240 minutes, in the case of the spray
painting only. However, when the gloves either had a small hole(s) or was torn after
moving sprayed \Mood panels to the collecting room, there was a positive result.
Therefore, F4 had positive indication of isocyanate on the fingers. The reasons for the
positive result are that F4 touched a hardener container, and the hands of the sprayer
\Mere contacted by thinners and acetone used to clean the spray gun and to prepare the
I.D.#Total isocyanate (pgNCO)
SG IDHSB ODHSBFI < 0.03 < 0.03 < 0.03
F2 < 0.03
130
spray paint. After 220 minutes, a positive result for HDI was obtained for the fingers,
due to physical damage on the gloves.
Table 45: Use of Permea-TecrM Pads for Hand Monitoring of Spray Painters
Wearing Protective Gloves (Disposable Nitrile Glove-TNT) - Group 4
#Monitoring relates to touch up spray painters (i.e. re-spraying imperfections)
Det. Conc.: Detected concentration, Samp. Time: Sampling time'
a: Spray painter,c: Spray painter, paint mixer and sander,e: Touched the Íìngers with thinner and acetone,g: A hole and damaged glove surface were observed.
b: Spray paint mixer,dr A hole was observed,f: Damaged glove surface by sanding,
3.4. 3. 2.4 PPE monitoring
PPE monitoring of the spray painters was conducted by wiping the respirator
(NORTON N7500 Series, Part No-022330, particulate and gas filter). No detectable
isocyanate (HDÐ was found from the inside of the respirator wiped after 4 minutes
aîd240 minutes.
I.D.#Sampling time
(minute)
Color reaction (P:positive, N:negative)
Left palm Risht nalm Left index Rieht index
Flu 7 N N N N
F2b 95 N N N N
F3u 180 N N N Pd
F2b 200 N N P" P"
F4' 220 N N Pf ps
Fl ' 240 N N N N
131
3.4. 3. 2. 5 Ocular monitoring
Ocular monitoring was conducted for one spray painter and the spray painter mixer
after finishing spray painting. Table 46 gives the results of the ocular monitoring. No
isocyanate was detected.
Table 46: Isocyanate Ocular Monitoring of Spray Painters in Furniture Industry inStudy Group 4
All subjects were touch up spray painters
<0.015 pgNCO; limit of detection
LD; limit of detection,
a: No protection
3 .4.4 Lab oratory Analysis
3.4.4.1 Optimized analytical conditions
3. 4. 4. I . I Abs orbing s o lution (D erivatizing S o lution)
Toluene and methylene chloride were compared, with regard to their use as a solvent
for 1-2MP (see section 3.3.2.I.4). Toluene was used in the HSE method (1999).
Different concentrations of 1-2MP in toluene and methylene chloride were used. A
known amount of hardener solution (6 pl of 0.04 ¡rgNCO/ml) was transferred in small
vials containing 10 ml of two different derivative solutions. Forthis analysis, HPLC
was used.
Table 47 g;ves the comparison of both chemical solutions in order to determine
isocyanate denvatization. It can be seen that methylene chloride and toluene give
similar results.
I.D.Total isocyanate (ueNCO)
Left eye Risht eve
FI < 0.015 < 0.015
F1u < 0.015 < 0.015
t3 < 0.015 < 0.015
t32
TabIe4T: Comparison Between Toluene and Methylene Chloride for DerivatizingSolution
Sample Recoverv rate (o/o) Mean (7o) STD
R-T
97.3
97.r 0.7796.297,7
R-MC
97.8
97.s 0.2597.3
97.4
R-T; Reference sample of Hardener in the derivatizing solution of 1-2MP in Toluene,R-MC; Reference sample of Hardener in the derivatizing solution of 1-2MP in Methylene Chloride
3. 4.4. 1 . 2 Dissolving solutions
Acetontrile is the solvent recommended by UK HSE for uptake of derivatised
isocyanate, although methanol has also been used to dissolve the urea (Pisaniello and
Muriale, 1989a). Table 48 gives the results of a comparison of different acetonitrile
and methanol mixtures. As can be seen, results are similar. The 90Yo methanol mix
appeared to be optimal in terms of urea dissolution.
Table 48: Isocyanate Extraction Eff,rciency of Different Acetonitrile:MethanolMixtures
R-Hard; Reference hardener sample dissolved in 100% acetonitrile (0.15 pg NCO/ml)H100M: Hardener sample extracted by 100% methanol,H90M: Hardener sample extracted by a mixture with 90% methanol and 10olo acetonitrileH50M: Hardener sample extracted by a mlxture with 50% methanol and 50olo acetonitrileH10M: Hardener sample extracted by a mixture with 10% methanol md 90o/o acetonitrile* The result could not be explained.
3.4.4.1.3 Ocular sdmpling solution ("Refresh" eye drops)
The rate of decomposition of isocyanate (technical grade hardener: PPG, 2K MS
Normal, 980-35239) in "Refresh" eye drops was evaluated. Table 49 gives the results.
SampleDetected concentration
(pgNCo/ml)Recovery rate (%o)
R-Hard 0.15 100
HIOOM 0,16 105
H9OM 0.18 t23*
H5OM 0.r4 96
HIOM 0.14 9l
133
SampleSampling time
(minute)
Total amount
(pe NCO)#
Recovery efficiency
(AM: %)
Reference* 0.49 100
Ocularsamplingsolution
"Refresh" eyedrops
I 0.07, 0.05, 0.06 I2
2 0.03, 0.03, 0.02 5
J 0.02,0.02,0.02 4
4 0.01,0.01,0.01 2
5 < 0.01 ¿.,
Table 49: Rate of Decomposition of HDl-based Hardener in Ocular SamplingSolution
# Each sample was run three times using HSE (2513) HPLC method.
* Technical grade hardener (2K MS PPG Hardener) dissolved in pure toluene
Although significant isocyanate degradation was found, it is not instantaneous and it
appears feasible to recover a small proportion of the original isocyanate, if the ocular
sampling (and derivatization) is conducted immediately after spraying.
3.4.4. 1.4 GhostrM Wipes
Isopropyl alcohol was ultimately used to wet surfaces prior to using dry GhostrM
V/ipes. However, two IPA compositions (50% in water and 100%) were tested under
different isocyanate loading conditions and delay times prior to derivatisation.
Table 50 gives the results.
On the basis of these data, it was decided that the most versatile wetting procedure
was2 sprays of 100% IPA.
t34
WettÍng Agent*No. of sprayapplications #
Time before placing in derivatizingsolution (min) @
Average recoveryfor isocvanate (Vol
50% IPA I Immediately (zero) 86
50% IPA 2 Immediately (zero) 83
50% IPA 5 Immediately (zero) 9l
5O% IPA 1 J 82
50% IPA 2 J 75
50% IPA 5 J 82
IOO% IPA 1 Immediately (zero) 70
lOO% IPA 2 Immediately (zero) 92
IOO% IPA 5 Immediately (zero) 88
lOO% IPA 1 J 88
1OO% IPA 2 J 81
lOO% IPA 5 3 80
Table 50: Efficiency of Isopropyl Alcohol as a Surface Wetting Agent
Each sample was run three times, and there were two wipes with GhostrM Wipe
30 ¡rl technical grade hardener (PPG) was applied on a smooth glass surface prior to wiping
* Wetting solution sprayed on pre-contaminated glass surface using â sprayer, 50% IPÀ is 507o isopropanol in distilledwatcrr 1007o IPA: Pure isopropanol
# Number of sprays from a dispenser of IPA solutions
@ After spraying wctt¡ng solution on glass surface, delay time of keeping GhostrM Wipe pads before derivatization.
3.4.4.2 Glove testing
3.4.4.2.1 Effect of solvents on selected gloves
In the crash repair shops, the spray workers used hardeners and thinners containing
xylene, toluene and cleaning agent (acetone). It was necessary to test the permeation
resistance of gloves against these component solvents.
Table 51 gives results with different solvents and glove materials tested. In this table,
it can be seen that the selected solvents passed through most of the glove materials
quickly. Disposable Latex Examination gloves gave the worst results with acetone,
xylene and toluene. Even when double thickness, BTs were considerably quicker than
others.
Nitrosolve gloves appear to have the best permeatin resistance, and were often used
for mixing paint and cleaning guns.
13s
ChemicalSubstance
Glove material Thickness (mm)IAM+ STD)
B.T ",(minute)
t00%Acetone
29-865 Ansell Neoprene 0.42 + 0.02 t0.2.10.2. t0.2
Latex Examination l) 0.12 + 0.01 < 1.00
Dermo Plus 2) 0.28 + 0.04 1.10.1.15.1.12
Nitrile TouchN TuffM 3)0.1 I + 0.00 < 1.00
22683 6 Nitrosolve MSArM 0.38 + 0.01 5.03, 5.03, 4.50
100%Xylene
29-865 Ansell Neoprene 0.42+0.02 '7.45.7.47.7.48
Latex Examination 0.14 + 0.01 < 1.00
Dermo Plus 0.28 + 0.02 8.14, 8.30, 8.40
Nitrile Touch N TufflM 0.12 + 0.01 2,47.2.50,2.45
22683 6 Nitrosolve MSArM 0.37 +0.02 69.5.78.5,74.2
100%Toluene
29-865 Ansell Neoprene 0.42 + 0.03 4.38,4.36,4.40Latex Examination 0.12 + 0.01 < 1.00
Dermo Plus 0.28 + 0.05 6.10.6.01,6.16
Nitrile Touch N TuffrM 0.12 + 0.00 0.58. 1.02. 1.05
22683 6 Nitrosolve MSArM 0.38 + 0.01 21.t.22.3,21.5
Table 51: Breakthrough Times of Glove Materials with Diverse Solvents
Each sample was run three times
1) Disposable latcx Examination Glove,2) Dermo Plus as a commercial product for kitchen,3) Disposable nitrile Touch N Tuff,4) Breakthrough time,
3.4.4.2.2 Effect of hardener strength on isocyqnate permeation
Gloves were tested aginst pure PPG hardener (980-35239) and 50% in xylene, using
the disposable permeation test cell.
Table 52 gives the results. Technical grade hardener was found to permeate more
slowly than the 50% solution. It can be seen that xylene appeared to encourage the
isocyanate to pass through the glove materials.
Disposable Latex Examination Gloves gave the shortest BTs compared with other
materials. It appears that these gloves should not be used for isocyanate spray painting
and the cleaning of tools, such as the spray gun and container. However, Nitrosolve
(226836) gloves appeared to be the best glove material for isocyanate protection, as
there was no detectable isocyanate after 8 hours.
136
Glove material Application Thickness (mm)(AM+STD)
BT O)
lmin)PR7)
(uslcm2/min)
Latex Examl)Purea) 0.12 + 0.01 1.s0. 1.s0. 1.40 0.15,0.17,0.175}Yos) 0.13 + 0.01 <l.00 0.16,0.17,0.16
Dermo Plus2)Pure 0.29 + 0.02 53.2,53.2.53.5 3.48, 3.56. 3.55
s0% 0.29 +0.02 31.3,3r.4,3r.3 2.26.2.32.2.1629-865Neoprene glove
Pure 0.41+0.02 8.0, 8.10, 8.0 2.46,2.69.2.1350% 0.42+0.02 5.2, 5.3, 5 .15 1.37 , 1.36, t.40
T N TTM3)Pure 0.12 + 0.01 3r.2,31.2,31.2 1.06, r.04, r.l450% 0.11 + 0.001 18.1.18.1.18.1 0.25,0.29,0.25
226836Nitrosolve
Pure 0.40 + 0.01 ND8) NDs0% 0.36 + 0.01 ND ND
Table 52: Breakthrough Times and Pemeation Rates of Selected Glove Materials
with Different Composition of Hardeners
Each sample \üas run three times
1) Latex Examination Glove,2) Dermo Plus as a commercial product for kitchens3) Disposable nitrile Touch N Tuff,4) Pure technical grade hardener,5) 50%o technical grade hardener in xylene,6) Breakthrough time,7) Permeation rate,8) Not detected within 8 hours
3.4.4.2.3 Fatigue test
Nitrosolve (226836) gloves were subjected to repeated washing in a washing machine
at 60oC. Permeation testing with the undiluted hardener (PPG; 2K MS Normal
Hardener 980-35239) in the disposable test cell was conducted. No isocyanate
breakthrough was evident after 8 hours even when gloves had been washed three
times.
There was also no significant difference in thickness between the unwashed new
gloves and the washed gloves.
3.5 Discussion
Evidence from animal studies (Zissu et al, 1998) suggests that dermal exposure to
isocyanates may contribute to the development of respiratory sensitization. However,
many questions remain about what form of exposure is most harmful, and the
biological mechanism of this harm (Sparer et a\,2004). Despite the attention given to
the control of inhalational exposure in the last 20 years, spray painters using
isocyanates are still over-represented in occupational asthma statistics in most
r37
countries. It is possible that lack of control of dermal exposure to isocyanates may be
partly responsible for the ongoing problem.
Studies of isocyanate exposure have been previously conducted in South Australia
(Pisaniello and Muriale, 1989a; Mohanu, 1996) but dermal and ocular exposures were
not assessed. This study sought to address this gap with a wide variety of methods.
Isocyanate spray painting in a sample of automobile repair workshops, training
workshops and a furniture manufacturer was investigated.
Laboratory tests of glove permeation resistance were carried out, and simple
disposable permeation cell was developed.
With respect to the research questions given in Chapter 1, the following conclusions
may be drawn:
o Evaluation of dermal exposures, in total and in respect to particular areas ofexposed skin, e.g. hands, and assessment of the opportunities of exposure;
Dermal exposure was evident when wipe samples were taken of the neck, forehead,
wrist and hands (Tables 33 and 34). Isocyanate (HDI) was detectable under thin latex
examination gloves, used during spray painting. Contamination of exposed skin areas
could occur even with relatively brief spraying periods.
Hand exposure could occur at all stages, e.g.mixing, spraying and cleanup.
Liu and coworkers (2000) found similar results, including facial contamination and
the poor performance of latex gloves. They argue that while hand contamination may
come from both direct contact, e.g. with work surfaces, and aerosol deposition, arm
and face contamination is more likely to result from vapour/aerosol deposition during
painting.
Significant dermal exposure was observed for outdoor and mobile spraying, due to
inappropriate PPE and uncontrolled ventilation.
It is important to note that hardeners with a much lower isocyanate content were used
in the furniture situation. No detectable isocyanate was found in the air or in eye, and
it was uncommon to find isocyanate on surfaces.
138
In this study, the overall airborne geometric mean isocyanate concentration in crash
repair workshops was 24 pgNCO/m3, which is marginally lower than other studies
(Liu et al., 2004; Sparer et ø1., 2004), probably due to different sampling and
analytical methods and the more widespread use of HVLP spray guns. In an earlier
study Pisaniello and Muriale (1989a) found an overall GM of 68 pgNCo/m3, but
HVLP guns were not used. V/ithout an extraction system, high airbome exposure
levels (0.55-2.4 mgNCO/mt¡ w"r" observed, due to use of low pressure spray guns
and low air velocities inside the spray booth. Cooper et al. (1993) considered not to
eliminate or minimize air contamination.. This issue has been discussed from both
theoretical (Carlton and Flynn, 1997) and empirical perspectives ('Woskie et a\,2004).
Table 53 indicates the proportion of positive results for skin wipe samples taken over
various regions of the body. Approximat ely 50Yo or more of the results were positive.
The OSHA Technical Manual (OSHA, 1999) suggests skin sampling in regions likely
to be exposed. However, neck and forehead regions are not mentioned. The data in
Table 53 would suggest that the neck and forehead are likely to yield positive results,
and should be included.
Table 53: Proportion of Detectable Dermal Isocyanate Exposures by Body Region
# Positive results over limits of detection.
o Evaluation of chemical contamination of the eye surface, arising from the spray
application of chemicals ;
Although isocyanates decompose in aqueous solutuion, the ocular sampling approach
described in this study was applicable as a semi-quantitative measure if the sampling
was done immediately after spraying. Tables 39 and 40 indicate that eye exposure is
Body region Total number ofsamples
Number of positiveresults# 7o positive
Neck 15 9 60Forehead 15 7 47Left back hand 15 9 60Right back hand 15 9 60Left palm 15 l2 80Rieht palm 15 10 67Left wrist 13 8 53Right wrist 13 7 47
r39
measurable when eye protection is not worn. Even if eye protection is worn, there is
potential for exposure via transfer from contaminated surfaces.
This appears to be the first study measuring eye exposure to isocyanates, and the
results point to the need for eye protection and good work practice.
o Prevalence of skin and eye-related symptoms, in absolute terms and in comparison
with a control group of unexposed workers;
Table 2l indicates that skin and respiratory synptoms are common among these spray
painters, This has been noted by others (Pisaniello and Muriale 1989b; Karol, 1986;
Belin et al I98l). Dry cracked skin, dermatitis/skin irritation and phlegm were
significantly more prevalent among exposed workers. In this study, skin symptoms
were likely to be from the accidental splashes on the body (the face, head, forehead,
lower arms and legs) during mixing, spraying and cleaning/washing equipment, or
perhaps spray painting at home, even though 85% of the exposed group had formal
training and education including in relation to health effects, PPE usage and MSDS.
Interestingly, eye irritation is less common, and this was also observed in a previous
study (Pisaniello and Muriale, 1989a). On the other hand, Randolph and coworkers
(1997) reported a greater extent of eye irritation. Conjunctivitis, a more severe eye
problem, was more common amongst the exposed (Hardy and Devine, 1979).
Comparison of measured exposures with observed work practice, equipment and
control measures;
This study (Table 26) shows that 460/o of painters spray outside of the dedicated
booth, compared with5go/o in 1988 (Pisaniello and Muriale, 1989) and25o/o in 1995
(Mohanu, 1996). The variation in percentages may reflect changing awareness or
levels of business activity relative to booth availability, but it is clear that such
spraying is common (Cullen et al., 1996). Bystander exposure may be significant
('Williams et a1.,I999;Líu et a1.,2004).
Isocyanate contamination was noted on peripheral surfaces (i.e. door handles, bench
tops and chemical balances), respirators and working tools (i.e. spray guns). However,
when the peripheral surfaces (i.e. chemical balance and door handles) were cleaned
a
140
after use, a negative result was reported - as in Table 36 (84). In particular,
isocyanate contamination was detected on the inside and outside of PPE (i.e. full face
air line respirator, half face respirators and safety goggles). The extent of
contamination inside the respiratory protection might provide an indication of the
potential for ocular exposure. More work is required to assess this.
Spray guns had obvious contamination after the spray painting was finished. PPE was
often selected or maintained inappropriately.
Before and after the spray painting, the spray painters put on the respiratory protection
or eye protection in contaminated areas andlor did not store them in an proper
container after cleaning. Cushmac et al., (1997) reported similar observations.
Two different kinds of disposable gloves were often used for spraying, i.e. disposable
latex examination gloves and disposable nitrile gloves. When the disposable latex
gloves rwere worn, hand exposure to isocyanate was evident. Even though hands could
be protected by wearing appropriate hand protection (disposable nitrile gloves),
significant glove damages (pinholes, abrasion etc.) were observed, particularly for the
fuiniture painters, e.g. as a result moving wood panels.
Finally, it appears the apprentices may be experiencing greater isocyanate exposure,
possibly due to poor work practice or less experience.
o Evaluation, where feasible, of uptake using biological monitoring methods and
correlation with ambient and dermal measurements;
As previously mentioned, there is presently no valid biological monitoring method
suitable for the quantitative assessment of isocyanate exposure when spraying HDI-
based paints (Liu, et a|,2004).
Assessment of PPE service life, in particular repeated usage of gloves, in actual
field use and in simulated laboratory experiments.
o
The permeation of isocyanates through gloves may be facilitated by the presence of
solvents such as xylene, commonly found in the paints. Table 51 shows that xylene
permeates more slowly through Nitrosolve gloves than Ansell neoprene gloves, even
though the gloves are of similar thickness (0.4 mm). Table 52 shows the same trend
t4t
for pure hardener and a 50% solution in xylene. Breakthrough of xylene occurs at 7-
minutes for the neoprene, and breakthrough of isocyanate occurs at about the same
time for this glove. On the other hand, isocyanate breakthrough was not detected for
Nitrosolve gloves, and is clearly much slower (53 and 3l min) than xylene
breakthrough (8 min) for Dermo Plus gloves. In general, however, the thicker the
glove material, the longer the BT.
When disposable gloves were tested in this study, monomeric HDI appeared to be
detectable in the HPLC chromatogram, soon after breakthrough occumed.
Higher molecular weight HDI oligomers occurred more commonly later. This
observation might be expected on the basis of molecular diffusion in the glove
material, and may have implications for worker health, if HDI monomer is more toxic
than the oligomers. Further work is warranted.
It appears that latex examination gloves are inferior to nitrile Touch N Tuff disposable
gloves, and the latter should be worn during spraying. Other researchers have noted
that disposable latex examination gloves failed to protect the hands (Mäkel e/
al.,2}03b). Abrasion and tearing of the gloves are also an important issue, particularly
in the fumiture industry.
Limitations
Although intensive monitoring was carried out, this study was limited in respect ofworker and worþlace sample size. The Motor Trade Association facilitated access to
worþlaces but only 50o/o agreed to participate. Skin and ocular sampling were
deemed to be more intrusive that air sampling.
Surface wipe sampling of irregular or porous surfaces is not straightforward and there
are uncertainties about transfer efficiency (Liu et al, 2000). This, coupled with the
reactivity of isocyanates, means that surface wipe results can only be regarded as
semi-quantitative.
The standard ASTM permeation test cell could not be used for isocyanates, due to the
chemical reaction with plastics and other surfaces. This prompted the development ofa disposable cell. Variable temperature, and usage experiments were not conducted,
athough a fatigue test was conducted with the Nitrosolve glove.
142
Strengths
This study has provided a wealth of information about surface contamination in
workshops, and the data are generally consistent with those recently reported
elsewhere (Liu et al., 20001, Sparer et al., 2004).It has measured ocular exposure for
the first time, and has looked at the furniture industry where hardeners of lower
isocyanate content are used. Exposures experienced by workers operating a franchised
mobile spray painting service were also investigated.
The use of HPLC methods in glove permeation testing has given an insight into the
relative permeation characteristics of oligomeric isocyanates.
Finally a simple low cost permeation testing system was developed.
Recommendations
The following recommendations can be made.
o Hardeners containing low levels of isocyanate should be used wherever possible.
o HVLP guns should be used.
o All spray paining work should be conducted in a dedicated spray booth.
o Disposable Touch N Tuff gloves should be used in preference to latex gloves for
spraying. Nitrosolve gloves should be used for mixing and cleaning up.
. Gloves and other PPE should be selected and stored appropriately, avoiding cross-
contamination.
. Any spills of hardener on surfaces should be immediately wiped up.
3.6 Conclusions
Exposure assessment for the spray painters using isocyanates included air monitoring,
surface and skin wiping, dermal exposure patches and eye fluid sample analysis.
V/orksite observation, health and work practice questionnaire and glove performance
tests were also conducted.
143
In this study, the availability of local exhaust ventilation and a high volume low
pressure (HVLP) spray gun correlated with lower airborne concentrations resulting in
the reduction of airborne and dermal exposure. Apprentice spray painters appeared to
have higher skin exposures, associated with poorer work practice. Similarly, outdoor
spraying was associated with greater skin contamination.
A high proportion of isocyanate wipe samples from crash repair shops were positive.
For instance, dermal exposure was detected on the neck, forehead, back hands, palms
and wrists. Surface contamination was obvious in worþlaces.
Eye contamination is an issue, unless either a full face air line mask or safety goggles
are wom during the spraying.
However, in the furniture factory, no detectable isocyanate was found in air, skin, eye
and surfaces samples, probably due to the low concentration of isocyanate in the
liquid hardener.
Isocyanate exposed painters experienced more skin and respiratory synptoms than the
controls. Eye irritation was uncoÍrmon.
For hand protection, gloves made of nitrile provided good protection unless there was
either physical damage or pre-contamination inside the gloves.
Isocyanate breakthrough was detected in a variety of disposable gloves. Where this
occurred, monomeric HDI was likely to be disproportionately more common than
oligomeric HDI, probably due to more facile diffusion of lower molecular weight
species. However, there was no detection of monomeric HDI after breakthrough
times. Thin latex gloves were commonly used but were found to provide little
resistance to permeation, according to the colorimetric observation using
PermeaTecrM pads underneath the gloves during working hours.
144
CHAPTER 4. GENERAL DISCUSSION
4.1 Dermal and Ocular Exposure during Spraying Processes
Spraying processes, as exemplified in the fruit fly, crash repair and fumiture
manufacturing industries, pose considerable potential for inhalational, dermal and
ocular exposure.
Inhalational exposure can be exacerbated by work in unventilated or uncontrolled
ventilation situations. Ocular exposure and dermal exposure to the face and arms
arises primarily from aerosol deposition. Even in controlled spray booth situations,
poor work practice and the wrong choice of PPE and spray equipment may result in
appreciable exposure.
The two studies described in Chapters 2 and 3 indicate that dermal exposure can occur
by direct contact (splash, leakage etc), secondary contamination (via contaminated
surfaces) or aerosol deposition. Measurements can be highly variable, but exposures
were determined around the neck, forehead, hands, wrists, forearms and chest.
Contamination of the shoulders and leg areas was visually observed.
These data are consistent with other studies that have looked a spraying processes
(Brouwer et aL,2000b).
Predictive models exist for inhalational exposure during spraying (Carlton and Flynn,
1997), with important factors being the orientation of the body relative to booth air
flow (freestream), use of HVLP spray guns, size and shape of the object, temporal
characteristics of spraying, variable spray gun to target distance etc. There is the
potential for interaction amongst factors, such that HVLP may not always yield lower
exposures (Carlton and Flynn, 1997). Ocular exposures may be predictable from
inhalational exposures given the proximity of the eye to the nose and mouth.
At present, it is not feasible to use these models effectively in real world situations.
Dermal exposure is even more complex, and much data, as well as professional
judgement, are required for semi-empirical approaches such as DREAM.
Visualization studies and whole body dosimetry methods provide direct answers but
are laborious and not always practicable.
r4s
V/ith regard to ocular exposure, research presented here provides prima facieevidence, at least in the case of isocyanates. However, such exposure could also be
inferred from forehead wipes, PPE contamination and air samples.
The data point to the need for appropriate eye protection. Surprisingly, eye irritation
does not figure prominently among reported symptoms, and the explanation is not
clear. One possibility is that the extent of eye exposure is minimal and the natural
ocular defences, e.g. production oftears, are sufficient.
Health questionnaires were used in both studies, with mixed success. Skin and
respiratory problems were identified among spray painters, in keeping with previous
research. Questionnaire approaches are valuable in that correlations between
symptoms and work practices can be investigated. However, such a cross sectional
approach is subject to survivor bias, such that those who experience problems are
more likely to leave the industry.
Splashes and other chemical accidents were common in both studies, and have been
noted elsewhere (Cattani et al,200l).
Biological monitoring was only used in the fiuit fly study, and the only conclusion to
be drawn is that body uptake is low. In general, however, biological monitoring has a
potentially important role in spraying situations where there is likely to be dermal
exposure, and a heavy reliance on PPE.
There is evidence from the study of crash repair workshops that HVLP spray guns and
proper spray booth ventilation do result in overall lower expsosures. However,
engineering controls do not completely remove the hazard of high aerosol
concentrations. Good work practices, personal hygiene and training, in the avoidance
of exposure, are equally important.
In both the fruit fly and spray painting situations, a common observation was
inappropriate storage of PPE and equipment, such that cross contamination is
possible. Eating and smoking whilst wearing contaminated PPE was also observed.
This can lead to eye and skin contamination, as well the possibility of ingestion. It can
reduce the effectiveness of respiratory protection, even if the correct cartridges are
used.
t46
Foot protection was also seen as inadequate. Some of the workers wore shoes which
had the potential to accumulate contaminants and provide ongoing exposure, e.g.
through persistent permeation. This issue requires further investigation.
Glove performance testing was a feature of this study, and it is clear that performance
depends on the glove type, usage pattem and temperature. The research supports the
arguments presented by Klingner and Boeniger (2002) in favour of greater attention to
in service testing. Key issues include the potential for differential wear, temperature,
mixed chemical exposures and physical pressures. It appears that employers and
workers are not aware of these issues.
In the case of the relatively thick PVC gloves used in fruit fly control, performace
deteriorated with no obvious change in appearance. Even when these is visible
evidence of damage, it appears that workers continue to use gloves.
The research highlights the need for a better understanding of the performance of PPE
in actual use. The research findings needs to be translated into guidance material for
users and distributors.
4.2 Further Studies
Dermal and ocular exposure to chemicals is a relatively new area, and further studies
are required. The work presented here would suggest the following:
Further in vitro or in vivo studies of chemical permeation through the
skin should be conducted. There is a need to better understand
transdermal penetration, including the influence of temperature, skin
wetness, the presence of an overlying glove material and chemical
mixtures. This information would greatly assist in assessing health
risks in situations where there is visible contamination of PPE, hot
conditions etc.
147
There should be more widespread testing of gloves used with
isocyanates. The disposable test cell has yield useful information, but
there are many gloves in use with many different isocyanate/solvent
mixtures. In this respect, it is heartening to note that funding has
recently been allocated for such work in the USA (Utrecht University
X200 4 Conference, 2004).
Ocular sampling methodologies should be further developed. There is
a need to better understand the significance of the ocular route, and the
influence of wearing contact lenses. Sampling protocols for dermal
exposure should include neck and forehead areas.
148
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APPENDICES
Appendix 1. Information Sheets, Consent and Complaint Forms
Appendix 1.1 Information sheet for fruit fly eradication workers
The University of Adelaide, Department of Public Health
INI'ORMATION SHEET F'OR WORKERS
Study of Dermal and Ocular Exposure to tr'ruit tr'ly Pesticides
The University of Adelaide is carrying out a study of chemicals used for fruit fly eradication. This studywill focus on exposure monitoring for fenthion and malathion, two organophosphorus pesticides approvedby the government.
One set of measurements will be of the concentrations of pesticides available to be breathed in, depositedon the skin or eye. The skin assessment will entail a wipe of exposed skin with a wiper, similar to a tissue.To assess whether or not traces of chemical are in your eye, we will ask you to put a couple of eye drops inyour eye, and then we will soak up the excess liquid from the corner of your eye with a sterile swab.
The other set of measurements will be one blood and two urine tests, collected at your workplace by anurse. We will also invite you to participate in a questionnaire survey, which will take around 5-10mlnutes.
The blood testing involves drawing blood from a vein which is the same procedure as when blood iscollected for any other blood test recommended by a medical practitioner.
If you want to find out the results of the tests, these results will be made available to you. When the finalreport is published no information will be released which will enable individuals to be identiflred.
The main purposes of the study are to clarify the extent of human exposure and to monitor effects whichmay occur following fruit fly treatment in the field with fenthion and malathion according to standardprocedures. There is very limited information about exposures, that is how much is taken up by the body,and it is imporlant to be able to monitor the effects of the pesticide once absorbed into the body. It is mostunlikely that any signihcant health effects will be observed in any situations, but we will be using aquestionnaire and very sensitive tests to pick up small changes.The results ofthis research should assist in developing policies on the sampling for hazardous chemicals. Itshould also assist in setting exposure standards and in formulating health surveillance programs and controlmeasures for pesticide-exposed workers.
If you would like further information or need assistance, please contact: Dr Dino Pisaniello, SeniorLecturer, Dept. of Public Health, University of Adelaide Ph: 8303 3571
An independent complaints procedure form will also be given to you, if you would like to lodge acomplaint about the conduct ofthe research.
180
Appendix 1.2 Information sheet for HDl-exposed workers
The University of Adelaide, Department of Public Health
INF'ORMATION SHEET F'OR WORKERS
Study of Dermal and Ocular Exposure to Isocyanates
The University of Adelaide is carrying out a study of chemicals used in the automobile and furniture
industries. This study will focus on exposures to isocyanates, used in two pack paints.
In this study we will be measuring concentrations of isocyanates available to be breathed in, deposited on
the skin or eye. The skin assessment will entail a wipe of exposed skin with a wiper, similar to a tissue. To
assess whether or not traces of chemical are in your eye, we will ask you to put a couple of eye drops in
your eye, and then we will soak up the excess liquid from the corner of your eye with a sterile swab.
We will also ask you to participate in a questionnaire survey, which will take around 5-10 minutes.
If you want to find out the results of the tests, these results will be made available to you. When the final
report is published no information will be released which will enable individuals to be identified.
The main purposes of the study are to clarify the extent of human exposure and to monitor effects which
may occur following the use of isocyanates according to standard procedures. There is very limited
information about exposures, that is how much is taken up by the body, and it is important to be able to
monitor the effects of the isocyanate once absorbed into the body. It is most unlikely that any significant
health effects will be observed in any situations, but we will be using a questionnaire and very sensitive
tests to pick up small changes.
The results of this research should assist in developing policies on the sampling for hazardous chemicals. It
should also assist in setting exposure standards and in formulating health surveillance programs and control
measures for isocyanate-exposed workers.
If you would like further information or need assistance, please contact:
Dr Dino Pisaniello, Senior LecturerDept. of Public Health, University of Adelaide Ph: 8303 3571
An independent complaints procedure form will also be given to you, if you would like to lodge a
complaint about the conduct ofthe research.
181
Appendix 1.3 Consent form for fruit fly eradication workers and HDl-exposed
workers
CONSENT F'ORM
The University of Adelaide
See also Information Sheet attached.
I (please print)
hereby consent to take part in the research project entitled:
Evaluation of dermal and ocular exposure to chemicals in South Australian workplaces
I acknowledge that I have read the Information Sheet.
I have had the project, so far as it affects me, fully explained to my satisfaction by the researchworker. My consent is given freely.
I have been given the opportunity to have a member of my family or a friend present while theproject was explained to me.
I have been informed that, while information gained during the study may be published, I will notbe identified and my personal results will not be divulged.
I understand that I am free to withdraw from the project at any time.
I am aware that I should retain a copy of this Consent Form, when completed, and the relevantInformation Sheet.
2.
J.
4.
5
6
,|
SIGNED DATE
NAME OF WITNESS SIGNED
I,
DATE
have described to
the nature ofthe procedures to be carried out. In my opinion, she/he understood the explanation.
SIGNED DATE
STATUS IN PROJECT
I82
Appendix 1.4 Complaint form
INDEPENDENT COMPLAINTS F'ORM
TTIE UNTVERSITY OF ADELAIDEHUMAN RESEARCH ETHICS COMMITTEE
Documentfor people wlto are subjects in a research project
CONTACTS FOR INFORMATION ON PROJECT AND INDEPENDENT COMPLAINTSPROCEDURE
The Human Research Ethics Committee is obliged to monitor approved research projects. In conjunctionwith other forms of monitoring it is necessary to provide an independent and confidential reportingmechanism to assure quality assurance of the institutional ethics committee system. This is done byproviding research subjects with an additional avenue for raising concerns regarding the conduct ofanyresearch in which they are involved.
The following study has been reviewed and approved by the University of Adelaide Human ResearchEthics Committee:
Project title:
Evaluation of dermal and ocular exposure to chemicals in South Australian workplaces
If you have questions or problems associated with the practical aspects of your participation in the
project, or wish to raise a concern or complaint about the project, then you should consult the project
co-ordinator:
I
Name:
Telephone
Dr Dino Pisaniello, Department of Public Health, University of Adelaide
8303 3s7r
2 If you wish to discuss with an independent person matters related to
. making a complaint, or
. raising concems on the conduct ofthe project, or
. the University policy on research involving human subjects, or
. your rights as a participant
contact the Human Research Ethics Committee's Secretary on phone (0S) 8303 4014
183
Appendix 2. Questionnaire
Appendix 2,1 Questionnaire for fruit fly eradication workers
Department of Public Health
Site Code
Worker Code
Date
Fruit FIv Pesticide Users Questionnaire
The following questionnaire is a part of a research project addressing
occupational health hazards in the pest control industry where malathion and
fenthion are used. The University of Adelaide is carrying out this research with
the assistance of Primary lndustries and Resources SA (PIRSA).
This questionnaire will obtain personal details, health effects and work practices.
It will be used to assist in evaluating dermal and ocular exposure. All information
will be strictly confidential and only be available to members of the University
research team and the individual concerned. No person will be identified and the
results will be reported anonymously.
The research will provide a broad picture of the industry and will allow us to make
specific recommendations that will lead to improved health and safety.
184
1. Name
PART A: Personal Information
Please tick the appropriate box or write
(Optional)
Month Year
2. Date of birth
Day
3. Sex
Female Male
4. Are you right or left handed?
5. Name of workplace
6. Job title (more than one option possible)
Team Leader Baiting Knocking Doors Others
7. Have you been using pesticides professionally before baiting work?
Yes No
lf yes,
How many years have you been using pesticides?
185
8. Have you had formal training in the use and application of pesticides?
Yes No
lf yes,
One day
More than one day
PART B: Health lnformation
Please tick the appropriate box or write
9. Do you currently suffer from
Hayfever
Asthma
Eczema
Any other skin problems
9(a). Did you suffer from asthma as a child?
Yes No
9(b). Do you get a more severe reaction than others to insect bites?
ves! ruo
10. Have you experienced dry cracked skin since starting baiting?
Y No
186
11. Have you experienced skin rash since starting baiting?
Ye No
12. Have you had dermatitis or skin irritation since starting baiting?
Ye No
lf yes, how frequently?
13. Have you had any eye problems since starting baiting?
Eye irritation
Itchy eyes
Dry eyes
Conjunctivitis
Any other eye problems
13(a) Have you experienced headaches during or after baiting?
Yes No
13(b) Have you had any unusual symptoms during or after baiting?
(e.9. tingling, weak muscles, loss of sensation)
14. Do you wear contact lenses?
Yes No
I87
15. Are you exposed to any pesticides outside of your regular working hours?
Yes No
16. Do you suffer from blackouts at work?
Yes No
17. Are you a smoker?
Current smoker Ex-smoker Never smoked
17(a). How many cigarettes do you smoke per day?
1-5 6-10 11-15 16-20 more than 20
PART C: Work Practices
Please tick the appropriate box or write
18. How much pesticide do you use? litre per day
19. How many hours do you spend spraying pesticides?
Min Hour per day
20. Apart from one day course, have you had any education and training about?
Health effects of pesticides
PPE
MSDSs
188
21. Have you had a major spill of pesticide product (500 mls or more)?
Yes No
lf yes,
Concentrate
Dilute
22 Have you had wet overalls from pesticide liquid leak or splash since startedin this week?
Yes No
23. Have you had an accident involving a splash in your eye?
Yes No
lf yes, how did it happen?
24. Have you had an accident splashing any other part of the body?
Yes No
lf yes, how did it happen?
189
25 what kinds of personal protective equipment do you wear regularly whenspraying pesticide?
Gas and particulate respirator-cartridge type
Particulate respirator-canister type
Overalls
Disposable Coveralls
Glasses (prescription lenses)
Goggles
Face shield
Gloves
26. Do you wear cotton under gloves?
Yes
No
lf yes,
Do you always wear under gloves when baiting?
Yes
27. What type of footwear do you use?
Shoes
Boots
No
190
27(a\. Are they your own?
Yes
28. ls all your other PPE supplied by your employer?
Yes No
lf yes, what ?
29 How frequently do you change your overalls?
davs
30. Do you clean/wash any of PPE yourself?
Shoes
Overalls
Respirator
Gloves
31 Do you completely remove your overalls (or other protective clothing)at lunch break?
Yes No
The end.
No
19l
Appendix 2.2 Questionnaire for isocyanate spray painters
Department of Public Health
Site Code
Worker Gode
Date
lsocvanate Users Questionnaire
The following questionnaire is a part of a research project addressing
occupational health hazards in the automotive and furniture industries where
isocyanate-based products are used. The University of Adelaide is carrying out
this research with the assistance of the Motor Trade Association.
This questionnaire will obtain information on personal details, health effects and
work practices. lt will assist in evaluating dermal and ocular exposure. All
information will be strictly confidential and only be available to members of the
University research team and the individuals concerned. No person will be
identified and the results will be reported anonymously.
The research will provide a broad picture of the industry and will allow us to make
specific recommendations that will lead to improved health and safety.
t92
1. Name
PART A: Personal lnformation
Please tick the appropriate box or write
(Optional)
Month Year
2. Date of birth
Day
3. Sex
Female Male
4. Are you right or left handed?
5. Name of workplace
6. Job title
7. How long have you been working in your current job?
8. How many years have you been using isocyanates as part of your current job?
Or, previous job?
9. Have you had formal training in the use of isocyanates based paints?
t93
PART B: Health lnformation
Please tick the appropriate box or write
10. Do you suffer from
Hayfever
Asthma
Eczema
Any other skin problems
10(a). Did you suffer from asthma as a child?
Yes No
10(b). Do you get a more severe reaction than others to insect bites?
Yes No
11. Have you experienced dry cracked skin at work in the last 12 months?
Yes No
12. Have you experienced skin rash at work in the last 12 months?
Yes No
13 During the past 12 months have you had dermatitis or skin irritation due toyour work?
Yes No
lf yes, how frequently?
t94
14. Do you usually cough during the day or night?
I'n the morning ! ouring the day At night
lf so, is there any particular activity or job which appears to make you cough?
15. Do you usually bring up any phlegm?
ln the morning ! Ouring the day At night
lf so, is there any particular activity or job which makes you phlegm?
1 5(a) ln the past 12 months, have you had a period of (increased) cough and phlegmlasting for three weeks or more?
Yes No
lf yes, why?
16. Have you ever had attacks of shortness of breath with wheezing?
Yes No
17. Does your chest ever feel tight or your breathing become difficult?
Yes No
i95
18. Have you had any eye problems in the last 12 months?
Eye irritation
Itchy eyes
Dry eyes
Conjunctivitis
Any other eye problems
19. Do you wear contact lenses?
Yes No
20. Have you experienced any work-related headaches in the last 12 months?
21. Do you suffer from blackouts at work?
Yes No
22. Are you a smoker?
Current smoker Ex-smoker Never smoked
22(a). How many cigarettes do you smoke per day?
1-5 6-10 11-15 16-20 more than 20
196
PART C: Work Practices
Please tick the appropriate box or write
23. What specific tasks do you carry out involving isocyanates?
Mixing
Spraying
Cleaning up
Other (Specify the description):
24. How much of hardener do you use? litre per day
25. How many hours do you spend for applying isocyanate-based paints?
Min Hour per day
26. Do you spray outside the booth with isocyanates paints?
Yes No
lf yes, how often do you do?
26(a). Are you exposed to isocyanates paints outside of your regular working hours?
Yes No
Have you had any specific education and training about isocyanatess withrespect to?
Health effects
PPE
MSDSs
27
r97
28. Are there work instructions/ procedures for isocyanates sprayers?
Yes No
29. Have you had a major spill of isocyanates product (S00 mls or more) ?
Yes No
30 Have you had an accident involving a splash of isocyanate-containing productsin your eyes?
Yes No lf yes, how did it happen?
31. Have you had an accident involving splashing any other part of the body?
Yes No lf yes, how did it happen?
32 What kind of personal protective equipment do you wear regularly whenspraying isocyanates or handling?
Full face-airline respirator
Half face-airline respirator
Hood or helmet-airline respirator
Air purifying cartridge respirator
Overalls
Disposable Coveralls
Glasses (prescription Ienses)
Goggles
Face shield
198
33. Do you wear gloves when spraying car?
Yes No
lf yes, what type of gloves do you use?
34. How often do you replace gloves?
Every time
Every four days
Everyday
Every five days
Every two days
Every six days
Every three days
Once a week
35. What type of footwear do you use?
Shoes
Boots
36. What type of spray gun do you use?
1 ) Type
2) Pressure:
37. ls all your PPE supplied by the employer?
Yes No lf yes, what ?
38. Do you clean/wash any of PPE by yourself?
Shoes
Overalls
Respirator
Gloves
199
39. Do you remove your overalls (or other protective clothing) at lunch breaks?
Yes No
40. Do you remove your overalls at the end of a day before going home?
Yes No
The end.
200
Appendix 2.3 Questionnaire for unexposed workers (Controls)
Department of Public Health
Site Code
Worker Code
Date
control Grou n Questionna¡re
The following questionnaire is part of a research project addressing the use of
certain hazardous chemicals in industry. We are particularly interested in skin
and eye exposure which may potentially lead to symptoms or more serious
health effects. ln order to assess the significance of symptoms reported by
workers in industry, we need to use a reference group of workers who are not
using the chemicals being studied.
You are part of this reference group. As a result of the study we should be able to
provide better advice on the safe use of chemicals at work.
All information that you give will be strictly confidential and only available to
members of the University research team and the individuals concerned. No
person will be identified and any results will be reported anonymously.
Now I am going to ask you questions mainly about health, but also about your
own use of chemicals.
201
PART A: Personal InformationPlease tick the appropriate box or write
L Name (Optional)
2. Year of birth
Year
3. Job title
4. Section of work
5. Major duties
6. Are you a full time or part time employee?
Full time
Part time
7. How many years have you been working with your current employer?
year(s)
8. What percentage of time do you spend outsides during working hours?
%
202
PART B: Health lnformationPlease tick the appropríate box or write
L Do you currentlv suffer from
Hayfever
Asthma
Eczema
Any other skin problems
10. Did you suffer from asthma as a child?
Yes No
lf YES, was it diagnosed by a doctor?
Yes No
10(a). Do you get a more severe reaction than others to insect bites?
Yes No
Skin Symptoms
11. Have you got any of the following symptoms now on your finger, hand,wrist or forearm?
1 1(a). Dry cracked skin due to work
Yes No
lf no, have you had this symptom in the last 12 months?
Yes No
203
1 1(b). Skin rash due to work
Yes No
lf no, have you had this symptom in the last 12 months?
Yes No
1 1(c). ltchy red skin
Yes No
lf no, have you had this symptom in the last 12 months?
Yes No
1 1(d). lnflamed (or swollen) skin
Yes No
lf no, have you had this symptom in the last 12 months?
Yes No
1 1(e). Any other skin symptoms?
Yes No
lf no skin problems, go to next section (respiratory symptoms)
12. How long have you had your skin problem?
1-11 months -2 years 3-5 years > 5 years
204
13. ln the last 12 months, did you have any medical treatment of your skinproblems?
Yes No
lf yes, what was the medical diagnosis?
I rritant contact dermatitis
Allergic contact dermatitis
Others
Don't know or can't remember
14 ln the last 12 months, did you lose any working days because of your skinproblems?
Yes No
lf yes, how many days/weeks in the last year have you been?
15. What do you think caused your skin problem?
Respiratory Symptoms
16. Do you usually cough during the day or night?
Yes No
If YES
ln the morning During the day At night
lf so, is there any particular activity or job which appears to make you cough?
20s
17. Do you usually bring up any phlegm?
Yes No
If YES
ln the morning During the day ! nt nist''t
lf so, is there any particular activity or job which gives you phlegm?
17(a). ln the past 12 months, have you had a period of (increased) cough and phlegmlasting for three weeks or more?
Yes No
18. Do you ever have attacks of shortness of breath with wheezing?
Yes No
19. Does your chest ever feel tight or your breathing become dífficult?
Yes No
lf YES to any of the above questions:
20. What do you think caused your respiratory problems?
206
21
Eye Symptoms
Have you experienced the following eye problems 3 or more times in thelast 12 months?
Eye irritation
Sore eyes
Itchy eyes
Watery eyes
Dry eyes
Burning eyes
Conjunctivitis
Any other eye problems
22
lf YES to any of the above:
What do you think caused your eye problem?
23. Do you wear contact lenses?
Yes No
Other symptoms
Have you experienced headaches 3 or more times at work in thelast 12 months?
24
207
26
25. Do you suffer from blackouts at work?
Yes No
Have you had any unusual symptoms from your work?
(e.9. tingling, weak muscles, loss of sensation)
Smoking
27. Are you a smoker?
Current smoker Ex-smoker Never smoked
27(a). How many cigarettes do you smoke per day?
1-5 6-10 11-15 16-20 more than 20
PART G: Chemical usage and work practicesPlease tick the appropriate box or write
Hobbies
28. Do you have any hobbies that entail significant use of chemical(s)?
Yes No
lf YES, describe the hobby(ies)
ChemÍcals at work
29. Do you use any chemical(s) as part of your work?
Yes No
lf NO to both questions then END.lf yes to either, answer the following questions
208
29(a). What type of the chemical(s)?
Solvent/Thi n ner/Petrol
Corrosive Chemical(s)
Pesticides
Paints
Adhesives
Cleaning agents
Any other chemicals
29(b). How much of the chemical(s) do you use?
litre/kg per week
29(c). How many hours per week on average do you use the chemicar(s)?
29(d). How many days per week do you use the chemical(s)?
days per week
29(e). For many years have you used the chemical?
30. Have you had a major spill of the chemical product (s00 mls or more) ?
Yes No
201)
31. Have you had an accident involving a splash in your eyes?
Yes No
lf yes, how did it happen?
32. Have you had an accident involving splashing any other part of the body?
Yes No
lf yes, how did it happen?
33. Do you wear personal protective equipment when handling the chemical(s)?
Yes No
lf yes, what kind of personal protective equipment do you wear?
If NO, ENDlf gloves indicated, then
34. What type of gloves do you use?
35. How often do you replace gloves?
Every time
Every four days
Everyday
Every five days
Every two days
Every six days
Every three days
Once a week
The end.
210
Appendix 2.4 Glove usage questionnaire for fruit fly eradication workers
The University of Adelaide, Department of Public Health
Fruit Fly Pesticide Exposure
STUDY OF GLOVES
Usage
YESBaiting only?
Mixing of concentrate?
Liners used?
Full days of usage
Has the glove been rinsed each day? YES
NO
NO
NO
days
NO
YES
YES
2tl
Appendix 3. Ethics Approval
Appendix 3.1 Flinders clinical research ethics committee (69/02)
I'linders Medtcal CentreBedford Park South Ausfralia 5042
Telephone (08) 8204 5511lRler¡ationel 618 B2û4 5511
Flinders Rssesrch Eth¡crr CÕmmítt€e Tetephone (08) 11204 ¡1507Fã¿ã¡mìtè (08) 8204 4006
€ftr¡lli eÆrcl.Hakçf@úììç,sÊ.F'¡,i,aìj1 3 Jury 20Ût
/\AEMORANDUMTO: Dr. J. Edwards, Occupational & Environmentåf HêêllhFROM: l'¡fs. C, Hgkof, Exect¡tive Officer, Flinders Citnical Res'eàroh Eth¡es commitieeTOFIC: Research Applicat¡on 6g/Gl
I am pleased to advìse lhat the Fl¡nders Cllnieal Researeh Ëlhies Commilt€e has approved yourreeearch appllcailon in accordance with the fcllowlng extract from the Minutes of its meétingheld on I July 20O1 ,
508S.31 Resoarch AÞÊlicållon 69¡0L- Dr.,J. ËdwârdsMonitoring changes in cho[inesterase enzyme açtivitias ift pest control workers withpotent¡al exposure lo chollneslerase-lnhiblting pestictd€s.Reviêw€r: Dr- R. GibeonThis application, as amended, was approved.
lf oondltlonal ('subjact to' or 'ín principte) approval is granted, research involving humansubj€ots may proeeed only after wrltten acceptanee of the cendltlonc of approval (ìnctudinga copy of the modilïcations) has beon recelved hy the Oommittee.Thls approvat l¡ for a perlod of c*e year. Applicallon for r'e.approval must be nraeleannualfy. Please note that lf thlç (rial lnvolves normal volunteers it will be necessary for you tokeep û record of thêir nârhr;ìs end you måy be roquirod to supply this list w¡lh your annual report.A copy of the s/gned conseat fornl fs fo be flled ln fhe sø[r¡'ac!,s modícal røcord,YoLr ãrc reminded thst the Fllnders Çllnical Reçeerch Elhics Cornm¡tt€e ntust apÞruve iheêonterìt and placement of adverli-çements for tl¡e recruit¡rrent of voluntesrs,The corÍm¡ttee rnusl be notif{Êd and approve any changes (e.g. additional proceduros,rnodificatlon of drug dosage, changes to inclusion or wlthdrawal crtterla, changes in mode andeont€flt oJ advÉrtlslng) in the invesligational plan pårtlcularty if these clranges lnvstve humansubjects,Ttre safe and ethlcal conduct of I triãl ls entirefy the responsibmty of the tnvesllgators. Whlte lheËllnders Çlinical Research Ethics committee takes c€re tc revlew and gtvè advlce on theeonduct of trials, approvãl by the Çommlttee is not an aþsolutê çsnfirmatìsn of safety, nor docsepproval eltor ín any wey the obllgalions and responsibililles of inves€gato¡s.
1. Adverse effects of lhe project on subjscts, including the totâl numbêt of subjects recruited,and of steps taken to dealwlth these adverse effeets.
2- Olher unforeseen evÊnlË.
3. A change in the base for I deçision måde by the Çommlttee¡ e.g, new sclentffic infor¡natTon-tfrat may invalidate the Ethical intsgrity of the study,
lf patients are lnv¡lved the ohief investigator is alst responslble for the process of notiflcatlon,seeking epproval or permlssien of Depañménls, D¡vistons sr lndlvltJual coñsultañt$.
T¡tt FEodûB Clltìiffil R.ceaqtqn ElhtB csñ¡iìôû ¡t Þnstitulfit 0ßd cp€ralÊs k! F@rdsã@ wllh lhê NF0q@1 Hsdth êDd Mßdlcá¡ fies+årch çow¡rsNfiUonËl SlÉ1êmenl oÉ €tfi¡sl Cündrc{ In Rffif€reh lßoh¡rE HtffitrE (JmË r 9ggl
212
Appendix 3.2The human research ethics committee at the University of Adelaide
ll March 2003
Dr DL Pisaniello
Publlc Health
Dear Dr Pisaniello
PROJECT NO:H-68-2002
oFFlcE oF tHE DEpUTy VtCE-CHA¡¡CETLoR (RESEAFCS)
HELEN MALEYSECRETAFYHUMAN BESEARCH ETHICS COMMfÍTEE
IHE UNIVERSITY OF ÀOELAIDEsA 5005AUSIRÁUA
TEI."EPHO¡IE i€l I 8303 401 4FÂCSIMILE {ô1 I 6303 34t 7ema¡l: hdm,m¡lbyOadslald€,6d¡.ilCFICOS Provlder Numbôr OOf 23M
Evaluation ol dermal and ocular exposure to chemicals in South Aústratianworkplaces
I wrile to advise you that the Human Research Ethics Committee has approved the above project.Please refer lo the enclosed endorsement sheet for further details and conditions that may beapplicable to this approval.
Where possible, subjects taking part in the study shoqld be given a copy of the lnformation Sheet andthe signed Consenl Form to retain. ,
A standard annual renewal and progress report form is available from the Committee's website.Please submit lhis prior to the above expiry date.
Yours sincerely
?hlCE MORTENSEN| | conu.not
Human Research Elhics Committee
2r3
OFFICE OF THE DEPUTY VICE.CHANCEIJ.OR (RESEÂRCH}
HELEil T¡ÂLBYSECRETARYHUMAN RESEARCH EÍHICS COMMTTEE
THE UNIVERSlrY OF ADELAIDEs 5005AUSTRAUA
IEI.EPHoNE {€l 88303 4011FACStMil,E *€1 0 8it03 34t7måll: hels malby0 addaldo.e{rJ.auCRICIS Prwld€r Numberml2gM
Applicant: Dr DL plsaniello
Deparlment Public Health
Proiecl Title; Evaluation of dermal and ocular exposure to chemicals in south Austratianworkplaces
THE UNIVERSITY OF ADEI-AIDE HUMAN RESEARCH ETHICS COMMITTEE
Proiect No: H'68'2002 BM No:oooomszs¡
APPROVED for the period until: 31 March 2004
on the basis of the supplementary information, amended information sheets and the Committee'scontacts/complaints document received on 17 .2.01.
Refer also- to the accompanying letter setting out requirements applying to approval.( Professor CE MortensenConvenor
Date: 13HAR2003
214
Page 1 of 1
Appendix 4. Cover Sheet of Laboratory Report f'rom WorkCover New South Wales
LABORATORY SERVICES UNITWoRKCoVËR
Dr J]# EdwardsEnvironmental HealthSchool of MedicineFlinders UniversityGPO Box 2100ADELAIDE SA 5OOI
Lab.Reference: 2001-2432-L
Your Reference:
REPORT OF ANALYSß
ï{TEW BOUIH WALEB
EMPLOYEE'SNAME:NAMEOFEMPLOYER:TYPE OF SAMPLE:
D'SYLVLA, PeierNot StatcdPre Shift U¡iae
DATEOFBIRTTI: NotSratedDATEOFCOLLECTION: 3o/lDt}t
DATE OF RECEIPT: 22ltttot
Somplæ Analysed as Received.
PESNCTDE
Urinary Cre¿tininc Result Uncertainty UnilsC¡eatinine 1.43 + 0.38 EILCreatinine (SI Unils) o.ol26 + 0.0033 moVL
BOEL: Biological occupatiomr Exposr¡c Limit (where a BOEL is not stat€d it is p€nding)ND: Not DetcctedNA: Not Applicable
tr'or ¡ddition¡l rdvice concernlng the lnterpreteüon ol the ¡bove re¡ul(s)contacl one ofour occuprtionrr physrcrrns rt rgorkcover NSlv (Ter: þi) 9370 s0o0)
See page 2 for additional i¡for¡¡¡tion about thc above test(s).
OrganophosphateMctabolites in Urine Scr
Result Unccrtainty BOEL Units
DMP ND +NA pmU¡ml creatinincDMTP ND +NA gnoVmol crcatinineDMDTP ND +NA pr¡oymol c¡eatinineDEP ND +NA
¡rmoVmol crcatinineDETP ND +NA
UmoVmol creatini¡eDEDTP ND +NA
FmoVmol creatininc
215
Appendix 5. Supporting Letter from Motor Trade Association17-sÉp-2w3 Lltøz FROH t4TÊ ¡ND{..rsTRtg_ \tr EE34ø?s P.øI/ø1.
THE MOTOR TRADE ASSOCTATION OF SOUTH AUSTRALIA INCORPORATEDAU¡T'MOT¡VE CENTI,F: OP IiXCI,LI.ENCÉ -t I¡RADERICI, ROAD. ROYAL IAR,K liÁ :T 14
t{, uox flo, tott ÁDE!.{toÉ sottllLEPtloNú tott t!¡t t0ótt ltEMl¡ ldrrr#w.Eh{¡.usÌ^(:srurr¡; r¡tjiår rorr fihjiri,ßîîär.,iliîo."r,,r0, ,*,
Dear rSql¡REquEsT FoR youR HELP -_!!-Elv_lEsFARcH ]NTO |SO_C-YANATE AESORpTtoN THROUGH9ÍI{EYE coNTAcr -+RÊLrMrNARy rÊsi¡Ho Äi'ùiÃ.crs, punrxen NDUsrRy woRKNEEDED.
en worklng wlth lhe MTA on tyÌyås a þcus on the health rfs liìng 2-pack palnls and annual
ûcrêåglng evldence a nd
f,."'"ìiiaffi[::FJJMTA GIS firund, (obvlously) that glove$ perlshed pn conüáor withs (mandetory et MTA GTs) shoul¿ be wo'm w¡lh arf te¡ Ì€;pifafure to avofa
WÌth thls ln mlnd, tha Universlty.would llke to vlelt a representative sample of collision reoairworkshops and bcus on Þossíble exposur_es throush tihe sÈtn. ïhd;;i ñï ffi,';ãs inctudingchanges to the way gloves, etc- are menuf¿ctured.- -
Ao in th!-ookne 'iÍl,il""o""l?fÍ.1i1Ìl':Jl'Jç,r*?',.ÍfliüTi,i"ffii.:'o
*Ftnattv. ovee w* be rösrãd rn *ri ia¡ó¡{'oìil f iËã¡iirË}iå,mrn.,å0a¡nst
:
ry
Thig ls an imporbñt piêcê of reseârch wñich wlfl be of bonçflt to lhe indusry and almr to öafeguardthe hÊalth ofall cgncerned.
There wlll be pracícal advrco to workshops, eupplrers and those rnvorved wirh trainíng,
The team comprlsee Dr Michael rkazcuk, Dr Drno p¡san¡eilo. end Mr sucir L€e.
11 September2003
rNamerrCompanyr
Paul EblênMánager, lndustrlal, Legal, OH&S and EnvlmnmÊnbl Sêrvlc€s.
W:lcoi¡rlqtlNousnoftts t Efrhqmrt¡t trEuFEUôlôdôìUnl gå t.fât to coil¡¡or RGp¡lrED doc
lssuesaerosols
2t6
Appendix 6. Worksite Observation Form
ÏHE UÊtrTfER$TTOFADELAIÐEd¡JSI*il[tA
Department of Public Health
Site Gode
Worker Code
Date
Work Site Observation Sheet
Company:Job Task:Job Location:
1. vy'orkshop size? Small (1-5 people) Medium (6-20 people) Large (over 2l people)
2. Work Procedures?
3. Working environment and workers behaviour?
4. Spray gun1) Manufacturer?2) Type?3) Pressure? (Kpa)
5. Ventilation system? Yes (Good, Good-fair, Fair, Fair-poor, poor) No
6. Chemical source present? Yes No
7. What kind of chemical agent used? Pesticide (malathion, fenthion), Isocyanate (HDI).Any Solvent?
8. Contamination? Surface Air Clothing Skin Eyes
9. Expected body part for contamination? Head, Neck, Ear, Eyes, upper arm, Lower arm, Forearm,Hands, Wrist, Waist, Upper leg, Lower leg, Ankle, Feet
10. Exposure route? Emission Deposition Transfer
217
1l. In the preparation and handling of a chemical source, emission to1) Clothing? U O R A2) Uncoveredskin? U O R A3)Eye? U O R A
* U; Unlikely (<17o of task duration) O: Occasionally (<107o of task duration)R: Repeatedly (10-50% of task duration) A: Almost constantly (>507o of task duration)
12. Visually estimated amount of emission? Small Medium Large
13. Deposition of spray mist to1) Clothing? U2) Uncovered skin? U3) Eye? U
AAA
RRR
ooo
14. Observational amount of deposition? Small Medium Large
l5. Transfer tol) Clothing?2) Uncovered skin?3) Eye?
* U: Unlikely (<l7o of task duration)R: Repeatedly (10-507" of task duration)
* U: Unlikely (<l %o of task duration)R: Repeatedly (10-507o of task duration)
16. Estimated amount of transfer?
17. Chemical properties?
Ol Occasionally (<107" of task duration)A: Almost constantly (>507o of task duration)
O: Occasionally (<107" of task duration)A: Almost constantly (>50yo of task duration)
ooo
UUU
RRR
AAA
Small
Solid
Low
Medium
Liquid
Medium
Large
Vapour mist
High18. Concentration of the used chemical?
19. Barrier cream used? Yes or NO
20. Cleaning after work completion? Worktable, Floor, Machines, Working tools,
21. What kind of PPE worn during1) Preparation?2) Application?3) Clean up?
22. Used PPE worn properly to reduce exposure? Yes No
r Emission: Mass transport of substances by direct release from a source onto skin or clothing, such asexposure by splashes, immersion ofhands into a liquid or powder (droplets and powder particles have anaerodynamic diameter of 100um).
r Deposition on skin or clothing: Mass transport from air. In this case, the contamination mæs (e.g. smallparticles with an aerodynamic diameter of <100 um, such as vapours, mist) is first released into the air andsubsequently deposited on skin or clothing.
. Transfer: The transfer of mass from contaminated surfaces onto skin or clothing, e.g. skin contact withsurfaces or working tools that have been previously contaminated with an agent.
*Source: van-Wendel-de-joode B., Brouwer D.H., Vermeulen R., van Hemmen J.J., Heederik D., and K¡omhout H.,, Ann. Occup. Hyg., Vol. 47, No. 1, ppTl-87,
2003.
218
